Kinetics study of hydrogen adsorption over Pt/MoO3 |
| |
| Authors: | Sugeng Triwahyono Aishah Abdul Jalil Sharifah Najiha Timmiati Nurun Najwa Ruslan Hideshi Hattori |
| |
| Affiliation: | 1. Ibnu Sina Institute for Fundamental Science Studies, Fac. of Science, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia;2. Dept. of Chemical Engineering, Fac. of Chemical and Natural Resources Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia;3. Catalysis Research Center, Hokkaido University, Sapporo 001-0021, Hokkaido, Japan;1. School of Chemistry and Environment, South China Normal University, Guangzhou 510006, China;2. Key Laboratory of Electrochemical Technology on Energy Storage and Power Generation of Guangdong Higher Education Institutes, South China Normal University, Guangzhou 510006, China;3. Engineering Research Center of Materials and Technology for Electrochemical Energy Storage (Ministry of Education), South China Normal University, Guangzhou 510006, China;1. School of Engineering, Indian Institute of Technology, Mandi, Himachal Pradesh, 175005, India;2. School of Basic Sciences, Indian Institute of Technology, Mandi, Himachal Pradesh, 175005, India;1. College of Materials Science and Engineering, Sichuan University, Chengdu 610065, China;2. Engineering Research Center of Alternative Energy Materials & Devices, Ministry of Education, Chengdu 610065, China |
| |
| Abstract: | The rate controlling step and the energy barrier involved in the hydrogen adsorption over Pt/MoO3 were studied. Rates of hydrogen adsorption on Pt/MoO3 were measured at the adsorption temperature range of 323–573 K and at the initial hydrogen pressure of 6.7 kPa. The rate of hydrogen uptake was very high for the initial few minutes for adsorption at and above 473 K, and reached equilibrium within 2 h. At and below 423 K, the hydrogen uptake still continued and did not reach equilibrium after 10 h. The hydrogen uptake exceeded the H/Pt ratio of unity for adsorption at and above 423 K, indicating that hydrogen adsorption involves hydrogen atom spillover and surface diffusion of the spiltover hydrogen atom over the bulk surface of MoO3 followed by formation of HxMoO3. The hydrogen uptake was scarcely appreciable for Pt-free MoO3. The rate controlling step of the hydrogen adsorption on Pt/MoO3 was the surface diffusion of the spiltover hydrogen with the activation energy of 83.1 kJ/mol. The isosteric heats of hydrogen adsorption on Pt/MoO3 were 18.1–16.9 kJ/mol for the hydrogen uptake range 2.4–2.8 × 1019 H-atom/g-cat. Similarities and differences in hydrogen adsorption on Pt/SO42?–ZrO2, Pt/WO3–ZrO2 and Pt/MoO3 catalysts are discussed. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
