Abstract
The water-gas shift reaction (WGSR) is an important industrial process for H2 production. Here, we rationally construct alumina supported dual-site copper catalysts, i.e. Cu~+ single atoms (Cu1~+) surrounding Cu nanoparticles (Cu_(NP)~0), for WGSR. Our findings show that CO is tightly adsorbed on surface-enriched Cu1~+ sites to inhibit competitive adsorption with H2O on Cu_(NP)~0 sites. The number of adsorbed CO is two orders of magnitude higher than that on conventional Cu-based catalysts. It significantly increases surface CO concentration, and forms a unique structure of Cu_(NP)~0 "islands" immerged in CO "pool". Benefiting from synergy of Cu1~+ and Cu_(NP)~0 sites, the catalyst with 12% Cu loading exhibits extraordinary and robust catalytic activity, compared to benchmark Cu-Zn-Al catalyst, especially at low temperatures, e.g. 200 °C. The catalyst design strategy and facile synthesis methodology employed in this work could be potentially applied in other related industrial reactions.
NSTL