Understanding the role of K on PtCo/Al2O3 for preferential oxidation of CO in H2

CO preferential oxidation reaction (CO-PROX) can effectively eliminate CO in H-2 rich atmosphere to avoid CO poison the Pt anode of Proton Exchange Membrane Fuel Cell (PEMFC). To match the operation temperature window for PEMFC, PtCo nanoparticles supported on K modified Al2O3 (PtCo/KeAl(2)O(3)) were prepared to promote CO-PROX activity. The addition of K species weakened the interaction between PtCo nanoparticle and support, which improved the dispersion of Pt particles and redox property of PtCo/Al2O3. It also facilitated the formation of Pt3Co species and active surface -OH groups, which were involved in CO-PROX reaction. According to in situ DRIFTS spectra, HCO3- and HCOO- were intermediates of PtCo/KeAl(2)O(3) catalyzed CO-PROX at low temperature and high temperature, respectively. Thus, the addition of 1 wt% K to PtCo/Al2O3 (PtCo/1KeAl(2)O(3)) could completely oxidize CO in the temperature range of 127-230 degrees C with O-2 selectivity at 50%. The 100% CO conversion temperature window of PtCo/1KeAl(2)O(3) is expanded by 100 degrees C in comparison of PtCo/Al2O3. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.