Influence of H2O and CO2 on the selective CO oxidation in H2-rich gases over Au/α-Fe2O3

Characterization of Active Sites/Entities and Redox/Catalytic Correlations in Copper-Ceria-Based Catalysts for Preferential Oxidation of CO in H2-Rich Streams

“…These are mostly employed and commercially available catalysts, although they exhibit a relatively low selectivity for the reaction of interest (CO oxidation) at practical operating temperature (between 373 and 473 K), which can make necessary interstage cooling operations to avoid extensive heating as a consequence of the exothermicity of the (H 2 and CO) oxidation reactions involved [9]. A second group of active catalysts involves supported gold catalysts, well known for their outstanding performance for CO oxidation [10][11][12][13][14]. These show a high CO-PROX activity with a good match between their activity window and the PEMFC anode operating temperature (353-403 K).…”

“…These show a high CO-PROX activity with a good match between their activity window and the PEMFC anode operating temperature (353-403 K). However, they can have the drawback of their poor resistance to the presence of CO 2 in the reactant mixture [3,11,12,15]. The third group is constituted by catalysts based on closely interacting copper oxide and ceria, which have shown promising properties in terms of activity, selectivity and resistance to CO 2 and H 2 O, while their lower cost (particularly in comparison to catalysts based on supported platinum, taking also into account the relatively high platinum loading required to optimize CO-PROX performance) could make them strongly competitive [3,4,6,7,[16][17][18][19][20][21][22][23][24].…”

Controlling activity and selectivity using water in the Au-catalysed preferential oxidation of CO in H2

“…The Au/Al 2 O 3 catalysts were more selective for PROX in our initial testing, so we focused additional studies on this system. Although the promotional effects of water in PROX have been reported 7,39 , there is no systematic study that seeks to control the activity and selectivity by adjusting the feed-water content. Herein we show that carefully controlling the feed-water content and space velocity (SV) leads to significant improvements in catalyst performance-far surpassing the 50/50 goal.…”

Au/CeO2 metallic monolith catalysts: influence of the metallic substrate

“…In the present case, the simultaneous coexistence with the CeO 2 layer of elements like Si, Ti, Fe and Al, for anodised aluminium, and Si, Fe and Cr, for Fecralloy monoliths, could improve the activity response towards CO oxidation, since mixed oxides based on them (Fe 2 O 3 , TiO 2 , CrO x , CeO 2 , etc.) have shown to be active catalysts and good supports in CO oxidation reactions [33][34][35][36][37][38]. This improvement is more significant for CeO 2 / Fecralloy monolith at low temperatures, reaching 50 % of conversion at 194°C.…”