Temperature-induced evolution of reaction sites and mechanisms during preferential oxidation of CO |
| |
| Authors: | Richard Kydd Davide Ferri Paul Hug Jason Scott Wey Yang Teoh Rose Amal |
| |
| Affiliation: | 1. ARC Centre of Excellence for Functional Nanomaterials, School of Chemical Engineering, University of New South Wales, Sydney, NSW 2052, Australia;2. Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Solid State Chemistry and Catalysis, Ueberlandstrasse 129, CH-8600 Dübendorf, Switzerland;1. Powder and Ceramics Division, Korea Institute of Materials Science (KIMS), Chang-won 641-831, Republic of Korea;2. Center for Nanomaterials and Chemical Reactions, Institute for Basic Science, Daejeon 305-701, Republic of Korea;3. Graduate School of EEWS, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea;4. Centre for Materials Architecturing, KIST, Seoul 136-791, Republic of Korea;1. Department of Chemical and Bio-molecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 Singapore, Singapore;2. Institute of Chemical and Engineering Sciences, A1STAR (Agency for Science, Technology and Research), 1 Pesek Road, Jurong Island, 627833 Singapore, Singapore;1. Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, China;2. School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China;1. Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China;2. Key Laboratory for Colloid and Interface Chemistry, Key Laboratory of Special Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China;1. School of Chemistry, Xi''an Key Laboratory of Sustainable Energy Materials Chemistry, State Key Laboratory of Electrical Insulation and Power Equipment, Xi''an Jiaotong University, Xi''an 710049, China;2. Laboratory of Inorganic Materials & Catalysis, Schuit Institute of Catalysis, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, the Netherlands;3. State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China |
| |
| Abstract: | Active sites responsible for the preferential oxidation of carbon monoxide were investigated using 4 wt.% Cu–CeO2 catalysts prepared by flame spray pyrolysis. Surface redox properties of the catalyst were assessed using a series of temperature-programmed reduction (CO, H2 and mixed) experiments, as well as operando infrared spectroscopy. It was demonstrated that CO and H2 react at identical surface sites, with CO2 formation proceeding simultaneously via three distinct Cun+–CO carbonyl species. The origin of high catalytic selectivity towards CO at below 150 °C stems from the carbonyl stabilization effect on the catalyst surface, preventing adsorption and subsequent oxidation of H2. Under non-selective conditions at higher temperatures, a gradual red-shift and loss of intensity in the carbonyl peak was observed, indicating reduction of Cu+ to Cu0, and the onset of an alternate redox-type oxidation mechanism where CO and H2 compete for the oxidation sites. These results for Cu–CeO2 suggest that improved low-temperature catalytic activity will only be achieved at the expense of reduced high-temperature selectivity and vice versa. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
