kowit lertwittayanon | Prince of Songkla University (original) (raw)

Papers by kowit lertwittayanon

Materials Science Forum

Direct ink writing was used for 3D printing of tubular Al2O3 membrane support. Agar-based ink mix... more Direct ink writing was used for 3D printing of tubular Al2O3 membrane support. Agar-based ink mixtures were prepared as a paste with a proper viscoelastic behavior in achieving printing. Using agar only for mixing with Al2O3 slurry in preparing the ink mixtures showed the flow behavior resulting in failure to print the Al2O3 tube due to too low viscosity of the ink mixture—100 Pa at 40°C. However, the introduction of Hydroxyethyl cellulose (HEC) as thickener and Polyethylene glycol 1500 (PEG 1500) as lubricant helped improve the behavior of the ink mixtures to be more proper paste for printing. The amounts of HEC were varied from 0 to 2wt% of solid loading. At 2wt% HEC, the ink mixture was able to be printed highest, compared to the other ink mixtures. However, the 2wt% HEC-using ink mixtures possessed the highest sintering shrinkage at 12%, while its relative density was highest at 70%. The results indicated that it was possible to print the alumina membrane tube if its fidelity wa...

International Journal of Biological Macromolecules

Materials Today: Proceedings

The alumina grinding beads are usually formed by a pan granulator method, however it is difficult... more The alumina grinding beads are usually formed by a pan granulator method, however it is difficult to form small size beads (1-2mm diameter). This work is focused on a new forming method which uses agar as gelling agent in gelcasting. The mixtures of alumina suspension and agar solution (concentration 1.5-4wt.%) are dropped into cooled oil using a pipette. The shape of mixture becomes sphere by its surface tension. After the mixture transformed to gel, it is separated from cooled oil. Later the gelled beads are dried in air and finally sintered at 1300-1400 degrees celsius. Tellus 46 oil is the cooled oil having the proper viscosity for forming. At 1.5wt.% concentration of agar solution, the shape of drop which is just dropped from the pipette tip is almost sphere. The sphere became better when final agar content increases from 0.25 to 1.0wt.%. However, at concentration [is more than or equal to] 2wt.% the shape of drop became more and more oval with increasing of the agar content. A...

Integrated Ferroelectrics, 2021

In this study, Pb(Mg1/3Nb2/3)0.65Ti0.35O3 (PMNT) ceramics were prepared by a water-based gel-cast... more In this study, Pb(Mg1/3Nb2/3)0.65Ti0.35O3 (PMNT) ceramics were prepared by a water-based gel-casting method. The gel-cast mixtures were dried through soaking in acetone with different soaking times (7, 10, 13, 16 and 19 days). Effects of acetone soaking times on phase, density, microstructure, dielectric, ferroelectric and piezoelectric properties of prepared ceramics were aimed to investigate. Acetone soaking time did not affect crystal structure and density of the prepared ceramics. Average grain size increased doubly as acetone soaking time raised up to 13 days. With increasing acetone soaking time, dielectric constant tended to increase while loss tangent decreased. The acetone soaking time of 7 days was found to be an optimum time period for drying gel-cast mixture which led to PMNT ceramics with optimum ferroelectric and piezoelectric properties, i.e. Pr, Ec, d 33 and g 33 of 21.8 µC/cm2, 7.8 kV/cm, 306 pC/N and 20.8 × 10−3 V⋅m/N, respectively, which were comparable to PMNT ce...

Disc alumina membrane supports were formed through agar gelcasting method. The agar gelcasting wa... more Disc alumina membrane supports were formed through agar gelcasting method. The agar gelcasting was expected to be environmentally-friendly forming technique using simple equipment. Final agar amounts (0.25 – 0.75wt%) in gelcasting mixtures were varied to find the optimum condition of shaping and the desired microstructure of sintered supports. The gelcasting mixtures were prepared from non-reactive grade Al 2 O 3 and porcelain at the ratio of 98.5:1.5 by weight. The porcelain addition allowed the membrane support to have high strength at lower sintering temperature. When the final agar amounts increased from 0.25 to 0.75wt%, the dried, gelcast supports tended to have rough surface and subsequently resulting in crack. TGA profiles confirmed that there was interaction between agar chains and kaolin particles on cooling the gelcast supports leading to different microstructures after sintering. The final agar amount of 0.5 wt% provided the highest porosity of 48.9% and the highest relat...

Tubular Al 2 O 3 membranes for microfiltration were successfully fabricated by combined steps of ... more Tubular Al 2 O 3 membranes for microfiltration were successfully fabricated by combined steps of agar gelcasting and then acetone-assisted drying. Firstly, Al 2 O 3 slurry and agar solution were separately prepared prior to being mixed together at a constant temperature of 70°C. Subsequently, the warm mixtures were poured into assembled glass mold and then rapidly transformed into gel with tubular shape. The as-gelled tubes were demolded and then soaked in acetone for 50 h allowing rapidly drying of the gel tubes after removal from acetone due to a lot of evaporation of acetone in air atmosphere at room temperature. The tubular Al 2 O 3 membranes were prepared from Al 2 O 3 powder with the significantly different particle sizes of ~5 µm and 0.167 µm at different proportions of 0.167 µm Al 2 O 3 powder from 5 to 20 wt%. The tubular Al 2 O 3 membranes possessed the range of linear drying and firing shrinkage of 8.5–11.5 and 0–0.75%, respectively. After sintering at 1300°C, all the tub...

International Journal of Hydrogen Energy, 2017

Ni/α-Al2O3 catalysts containing CaZrO3 nanoparticles as a promoter were prepared by sequential im... more Ni/α-Al2O3 catalysts containing CaZrO3 nanoparticles as a promoter were prepared by sequential impregnation for H2 production from steam-methane reforming. The effects of different loadings of CaZrO3 nanoparticles from 0 to 15 wt% on the catalytic performance of Ni/α-Al2O3 catalysts in steam-methane reforming were studied. The Ni/α-Al2O3 catalysts containing 15 wt% CaZrO3 nanoparticles provided the highest H2 yield due to facilitative steps of enormous steam adsorption-dissociation at the sites of oxygen vacancies on the surface of CaZrO3 nanoparticles. The existence of facilitative steps created additional H+ and OH− enhancing both H2 yield and the gasification of deposited carbon, respectively. The tests of steam-methane reforming at low S/C ratio of 1/3 for 97 h revealed that the catalytic performance of CaZrO3-modified Ni/α-Al2O3 catalysts was higher than that of the unmodified Ni/α-Al2O3 catalyst. Interestingly, at high S/C ratio of 3 excessive steam adsorption at the oxygen vacancies on CaZrO3 nanoparticles resulted in highly competitive adsorption between steam and methane decreasing CH4 dissociation. The results suggested that in the steam-methane reforming, optimum S/C ratios for the CaZrO3-modified Ni/α-Al2O3 catalysts were relatively lower than those for the unmodified Ni/α-Al2O3 catalyst due to excellent steam adsorption-dissociation capability for CaZrO3 nanoparticles.

Journal of Forestry Research, 2018

Physicochemical characteristics and in vitro antioxidant activities of four pyroligneous acids ca... more Physicochemical characteristics and in vitro antioxidant activities of four pyroligneous acids carbonized from the wastes of wood species including Mangosteen (Garcinia mangostana Linn.), Durian (Durio zibethinus L.), Rambutan (Nephelium lappaceum L.), and Langsat (Lansium domesticum Serr.) were assessed. Appearing as transparent liquors with pH 3.9–4.2, the pyroligneous acid samples under test possessed acetic acid (23.22–25.46%) as the dominant component. The total soluble tar, total acid, and water content were 0.15 − 0.28 wt%, 99–192 mg KOH/g and 84.5–93.5 wt%, respectively. Phenolic compounds namely: 2,6-dimethoxyphenol (6.88–9.69%), phenol (2.97–5.88%), 4-methylsyringol (3.10–3.56%), guaiacol (2.36–3.55%), and 2-methoxy-4-methylphenol (1.08–1.28%) were found. All had in vitro antioxidant activities especially mangosteen pyroligneous acid, which showed activity roughly similar to BHT (P > 0.05) against anti-lipid peroxidation. Nitric oxide scavenging capacities of all pyroligneous acids were significantly higher than BHT (P < 0.05). Our results suggest that pyroligneous acids from the four types of branch waste could be used as sources of beneficial natural antioxidants, possibly as food or feed additives to protect against lipid peroxidation, and potentially also in veterinary medicine in anti-inflammatory products.

Key Engineering Materials, 2016

In this work, Pd metal layer was deposited on in-house prepared macro-porous disc alumina support... more In this work, Pd metal layer was deposited on in-house prepared macro-porous disc alumina support by electroless plating. The in-house prepared support were repeatedly seeded for 4 cycles to obtain Pd nuclei before repeatedly electroless plated for 4 cycles. The 4-cycle Pd plating was to obtain the full layer of Pd metal observing from changing support surface from black to light grey. The plated membrane samples were annealed at 550 and 600oC for using in high-temperature H2 separation. The annealed samples were observed morphology by SEM and confirm the occurrence of Pd layer with EDS. The SEM images revealed incomplete Pd layer. The over 4 cycles of plating were needed to form complete Pd layer since the numerous Pd ions diffused into macro-pores alumina support instead of depositing on the surface of macro-porous support. The higher annealing temperature of 600oC led to denser layer of Pd with the presence of small cracks due to the contraction of Pd particles.

RSC Adv., 2015

Performances of a novel PVDF–Cloisite 15A hollow fiber composite membrane in treating a dyeing so... more Performances of a novel PVDF–Cloisite 15A hollow fiber composite membrane in treating a dyeing solution containing 50 ppm AR1 and 0.1–1.0 M NaCl.

International Journal of Hydrogen Energy, 2010

Fuel and Energy Abstracts, 2010

A liquid drying agent, i.e. acetone, was employed for allowing the faster drying of Al2O3 tubes f... more A liquid drying agent, i.e. acetone, was employed for allowing the faster drying of Al2O3 tubes fabricated by agar gelcasting than the conventional air drying. The mixture of Al2O3 slurry and agar solution was separately prepared and then mixed prior to molding out of a set of warmed glass tubes. After the mixture transformed into gelled tube, the gelled tube was demolded and then immersed in acetone at different periods of time from 0 to 50 h. The immersed periods of 50 h led to the acetone replacement for water being inside of the gelling tube by 74 wt.% and then shortened the drying period to be 25 min. On the other hand, the conventional air drying spent 420 min drying completely. After drying, the immersed tubes possessed spherical cross section; whereas, no immersed tubes showed the deformation of cross section. The shortened drying was in line with the smaller drying shrinkage (4.7%), broader pore-size distribution and higher porous microstructure, comparing to the convention...

Fuel and Energy Abstracts, 2010

Ni catalyst Calcium zirconate Perovskite structure a b s t r a c t Ni catalysts supported on (CaO... more Ni catalyst Calcium zirconate Perovskite structure a b s t r a c t Ni catalysts supported on (CaOeZrO 2 )-modified g-Al 2 O 3 were prepared by sequential impregnation. The effects of varied CaO to ZrO 2 mole ratios at 0, 0.20, 0.35, 0.45, and 0.55 on the activity and stability of the modified Ni catalysts were studied. As a result of using CaOeZrO 2 as a promoter, each catalyst contained CaOeZrO 2 at only 5%. g-Al 2 O 3 used as support was modified by CaOeZrO 2 before the deposition of nickel oxide. The addition of CaOeZrO 2 at an optimum ratio was expected to improve the stability of Ni catalysts due to the decrease of carbon formation resulting from carbon gasification. All the fresh catalysts were characterized by ICP, XRD, BET surface area, TGA in H 2 , and TPR before catalytic testing in steam methane reforming at 600 C. The spent catalysts were examined by TEM and TGA to observe the catalysts deactivation. The identification of CaOeZrO 2 phases indicated that CaO and ZrO 2 reacted with each other to be monoclinic solid solution ZrO 2 , CaZr 4 O 9 , CaZrO 3 , and CaO corresponding to the phase diagram of CaOeZrO 2 . The existence of CaZrO 3 for 0.55 mol ratio of CaO/ZrO 2 enhanced activity in steam methane reforming because oxygen vacancies in CaZrO 3 greatly preferred the water adsorption creating the favorable conditions for carbon gasification and, then, water gas shift. The prominence and continued existence of these two reactions on the Ni catalysts leads to the particular increase of H 2 yield. Moreover, the increasing amount of CaZrO 3 in the Ni catalysts significantly improved carbon gasification. However, the Ni catalysts with CaZrO 3 showed whisker carbon after catalytic testing; this carbon specie has not been tolerated in steam methane reforming. Therefore, these results significantly differed from the hypothesis. .th (V. Sricharoenchaikul).

Materials Science Forum

Direct ink writing was used for 3D printing of tubular Al2O3 membrane support. Agar-based ink mix... more Direct ink writing was used for 3D printing of tubular Al2O3 membrane support. Agar-based ink mixtures were prepared as a paste with a proper viscoelastic behavior in achieving printing. Using agar only for mixing with Al2O3 slurry in preparing the ink mixtures showed the flow behavior resulting in failure to print the Al2O3 tube due to too low viscosity of the ink mixture—100 Pa at 40°C. However, the introduction of Hydroxyethyl cellulose (HEC) as thickener and Polyethylene glycol 1500 (PEG 1500) as lubricant helped improve the behavior of the ink mixtures to be more proper paste for printing. The amounts of HEC were varied from 0 to 2wt% of solid loading. At 2wt% HEC, the ink mixture was able to be printed highest, compared to the other ink mixtures. However, the 2wt% HEC-using ink mixtures possessed the highest sintering shrinkage at 12%, while its relative density was highest at 70%. The results indicated that it was possible to print the alumina membrane tube if its fidelity wa...

International Journal of Biological Macromolecules

Materials Today: Proceedings

The alumina grinding beads are usually formed by a pan granulator method, however it is difficult... more The alumina grinding beads are usually formed by a pan granulator method, however it is difficult to form small size beads (1-2mm diameter). This work is focused on a new forming method which uses agar as gelling agent in gelcasting. The mixtures of alumina suspension and agar solution (concentration 1.5-4wt.%) are dropped into cooled oil using a pipette. The shape of mixture becomes sphere by its surface tension. After the mixture transformed to gel, it is separated from cooled oil. Later the gelled beads are dried in air and finally sintered at 1300-1400 degrees celsius. Tellus 46 oil is the cooled oil having the proper viscosity for forming. At 1.5wt.% concentration of agar solution, the shape of drop which is just dropped from the pipette tip is almost sphere. The sphere became better when final agar content increases from 0.25 to 1.0wt.%. However, at concentration [is more than or equal to] 2wt.% the shape of drop became more and more oval with increasing of the agar content. A...

Integrated Ferroelectrics, 2021

In this study, Pb(Mg1/3Nb2/3)0.65Ti0.35O3 (PMNT) ceramics were prepared by a water-based gel-cast... more In this study, Pb(Mg1/3Nb2/3)0.65Ti0.35O3 (PMNT) ceramics were prepared by a water-based gel-casting method. The gel-cast mixtures were dried through soaking in acetone with different soaking times (7, 10, 13, 16 and 19 days). Effects of acetone soaking times on phase, density, microstructure, dielectric, ferroelectric and piezoelectric properties of prepared ceramics were aimed to investigate. Acetone soaking time did not affect crystal structure and density of the prepared ceramics. Average grain size increased doubly as acetone soaking time raised up to 13 days. With increasing acetone soaking time, dielectric constant tended to increase while loss tangent decreased. The acetone soaking time of 7 days was found to be an optimum time period for drying gel-cast mixture which led to PMNT ceramics with optimum ferroelectric and piezoelectric properties, i.e. Pr, Ec, d 33 and g 33 of 21.8 µC/cm2, 7.8 kV/cm, 306 pC/N and 20.8 × 10−3 V⋅m/N, respectively, which were comparable to PMNT ce...

Disc alumina membrane supports were formed through agar gelcasting method. The agar gelcasting wa... more Disc alumina membrane supports were formed through agar gelcasting method. The agar gelcasting was expected to be environmentally-friendly forming technique using simple equipment. Final agar amounts (0.25 – 0.75wt%) in gelcasting mixtures were varied to find the optimum condition of shaping and the desired microstructure of sintered supports. The gelcasting mixtures were prepared from non-reactive grade Al 2 O 3 and porcelain at the ratio of 98.5:1.5 by weight. The porcelain addition allowed the membrane support to have high strength at lower sintering temperature. When the final agar amounts increased from 0.25 to 0.75wt%, the dried, gelcast supports tended to have rough surface and subsequently resulting in crack. TGA profiles confirmed that there was interaction between agar chains and kaolin particles on cooling the gelcast supports leading to different microstructures after sintering. The final agar amount of 0.5 wt% provided the highest porosity of 48.9% and the highest relat...

Tubular Al 2 O 3 membranes for microfiltration were successfully fabricated by combined steps of ... more Tubular Al 2 O 3 membranes for microfiltration were successfully fabricated by combined steps of agar gelcasting and then acetone-assisted drying. Firstly, Al 2 O 3 slurry and agar solution were separately prepared prior to being mixed together at a constant temperature of 70°C. Subsequently, the warm mixtures were poured into assembled glass mold and then rapidly transformed into gel with tubular shape. The as-gelled tubes were demolded and then soaked in acetone for 50 h allowing rapidly drying of the gel tubes after removal from acetone due to a lot of evaporation of acetone in air atmosphere at room temperature. The tubular Al 2 O 3 membranes were prepared from Al 2 O 3 powder with the significantly different particle sizes of ~5 µm and 0.167 µm at different proportions of 0.167 µm Al 2 O 3 powder from 5 to 20 wt%. The tubular Al 2 O 3 membranes possessed the range of linear drying and firing shrinkage of 8.5–11.5 and 0–0.75%, respectively. After sintering at 1300°C, all the tub...

International Journal of Hydrogen Energy, 2017

Ni/α-Al2O3 catalysts containing CaZrO3 nanoparticles as a promoter were prepared by sequential im... more Ni/α-Al2O3 catalysts containing CaZrO3 nanoparticles as a promoter were prepared by sequential impregnation for H2 production from steam-methane reforming. The effects of different loadings of CaZrO3 nanoparticles from 0 to 15 wt% on the catalytic performance of Ni/α-Al2O3 catalysts in steam-methane reforming were studied. The Ni/α-Al2O3 catalysts containing 15 wt% CaZrO3 nanoparticles provided the highest H2 yield due to facilitative steps of enormous steam adsorption-dissociation at the sites of oxygen vacancies on the surface of CaZrO3 nanoparticles. The existence of facilitative steps created additional H+ and OH− enhancing both H2 yield and the gasification of deposited carbon, respectively. The tests of steam-methane reforming at low S/C ratio of 1/3 for 97 h revealed that the catalytic performance of CaZrO3-modified Ni/α-Al2O3 catalysts was higher than that of the unmodified Ni/α-Al2O3 catalyst. Interestingly, at high S/C ratio of 3 excessive steam adsorption at the oxygen vacancies on CaZrO3 nanoparticles resulted in highly competitive adsorption between steam and methane decreasing CH4 dissociation. The results suggested that in the steam-methane reforming, optimum S/C ratios for the CaZrO3-modified Ni/α-Al2O3 catalysts were relatively lower than those for the unmodified Ni/α-Al2O3 catalyst due to excellent steam adsorption-dissociation capability for CaZrO3 nanoparticles.

Journal of Forestry Research, 2018

Physicochemical characteristics and in vitro antioxidant activities of four pyroligneous acids ca... more Physicochemical characteristics and in vitro antioxidant activities of four pyroligneous acids carbonized from the wastes of wood species including Mangosteen (Garcinia mangostana Linn.), Durian (Durio zibethinus L.), Rambutan (Nephelium lappaceum L.), and Langsat (Lansium domesticum Serr.) were assessed. Appearing as transparent liquors with pH 3.9–4.2, the pyroligneous acid samples under test possessed acetic acid (23.22–25.46%) as the dominant component. The total soluble tar, total acid, and water content were 0.15 − 0.28 wt%, 99–192 mg KOH/g and 84.5–93.5 wt%, respectively. Phenolic compounds namely: 2,6-dimethoxyphenol (6.88–9.69%), phenol (2.97–5.88%), 4-methylsyringol (3.10–3.56%), guaiacol (2.36–3.55%), and 2-methoxy-4-methylphenol (1.08–1.28%) were found. All had in vitro antioxidant activities especially mangosteen pyroligneous acid, which showed activity roughly similar to BHT (P > 0.05) against anti-lipid peroxidation. Nitric oxide scavenging capacities of all pyroligneous acids were significantly higher than BHT (P < 0.05). Our results suggest that pyroligneous acids from the four types of branch waste could be used as sources of beneficial natural antioxidants, possibly as food or feed additives to protect against lipid peroxidation, and potentially also in veterinary medicine in anti-inflammatory products.

Key Engineering Materials, 2016

In this work, Pd metal layer was deposited on in-house prepared macro-porous disc alumina support... more In this work, Pd metal layer was deposited on in-house prepared macro-porous disc alumina support by electroless plating. The in-house prepared support were repeatedly seeded for 4 cycles to obtain Pd nuclei before repeatedly electroless plated for 4 cycles. The 4-cycle Pd plating was to obtain the full layer of Pd metal observing from changing support surface from black to light grey. The plated membrane samples were annealed at 550 and 600oC for using in high-temperature H2 separation. The annealed samples were observed morphology by SEM and confirm the occurrence of Pd layer with EDS. The SEM images revealed incomplete Pd layer. The over 4 cycles of plating were needed to form complete Pd layer since the numerous Pd ions diffused into macro-pores alumina support instead of depositing on the surface of macro-porous support. The higher annealing temperature of 600oC led to denser layer of Pd with the presence of small cracks due to the contraction of Pd particles.

RSC Adv., 2015

Performances of a novel PVDF–Cloisite 15A hollow fiber composite membrane in treating a dyeing so... more Performances of a novel PVDF–Cloisite 15A hollow fiber composite membrane in treating a dyeing solution containing 50 ppm AR1 and 0.1–1.0 M NaCl.

International Journal of Hydrogen Energy, 2010

Fuel and Energy Abstracts, 2010

A liquid drying agent, i.e. acetone, was employed for allowing the faster drying of Al2O3 tubes f... more A liquid drying agent, i.e. acetone, was employed for allowing the faster drying of Al2O3 tubes fabricated by agar gelcasting than the conventional air drying. The mixture of Al2O3 slurry and agar solution was separately prepared and then mixed prior to molding out of a set of warmed glass tubes. After the mixture transformed into gelled tube, the gelled tube was demolded and then immersed in acetone at different periods of time from 0 to 50 h. The immersed periods of 50 h led to the acetone replacement for water being inside of the gelling tube by 74 wt.% and then shortened the drying period to be 25 min. On the other hand, the conventional air drying spent 420 min drying completely. After drying, the immersed tubes possessed spherical cross section; whereas, no immersed tubes showed the deformation of cross section. The shortened drying was in line with the smaller drying shrinkage (4.7%), broader pore-size distribution and higher porous microstructure, comparing to the convention...

Fuel and Energy Abstracts, 2010

Ni catalyst Calcium zirconate Perovskite structure a b s t r a c t Ni catalysts supported on (CaO... more Ni catalyst Calcium zirconate Perovskite structure a b s t r a c t Ni catalysts supported on (CaOeZrO 2 )-modified g-Al 2 O 3 were prepared by sequential impregnation. The effects of varied CaO to ZrO 2 mole ratios at 0, 0.20, 0.35, 0.45, and 0.55 on the activity and stability of the modified Ni catalysts were studied. As a result of using CaOeZrO 2 as a promoter, each catalyst contained CaOeZrO 2 at only 5%. g-Al 2 O 3 used as support was modified by CaOeZrO 2 before the deposition of nickel oxide. The addition of CaOeZrO 2 at an optimum ratio was expected to improve the stability of Ni catalysts due to the decrease of carbon formation resulting from carbon gasification. All the fresh catalysts were characterized by ICP, XRD, BET surface area, TGA in H 2 , and TPR before catalytic testing in steam methane reforming at 600 C. The spent catalysts were examined by TEM and TGA to observe the catalysts deactivation. The identification of CaOeZrO 2 phases indicated that CaO and ZrO 2 reacted with each other to be monoclinic solid solution ZrO 2 , CaZr 4 O 9 , CaZrO 3 , and CaO corresponding to the phase diagram of CaOeZrO 2 . The existence of CaZrO 3 for 0.55 mol ratio of CaO/ZrO 2 enhanced activity in steam methane reforming because oxygen vacancies in CaZrO 3 greatly preferred the water adsorption creating the favorable conditions for carbon gasification and, then, water gas shift. The prominence and continued existence of these two reactions on the Ni catalysts leads to the particular increase of H 2 yield. Moreover, the increasing amount of CaZrO 3 in the Ni catalysts significantly improved carbon gasification. However, the Ni catalysts with CaZrO 3 showed whisker carbon after catalytic testing; this carbon specie has not been tolerated in steam methane reforming. Therefore, these results significantly differed from the hypothesis. .th (V. Sricharoenchaikul).