Low Loading Pt Single Atoms Supported on Kit-6-Functionalized Sm0.8sr0.2coo3 for Water Gas Shift Reaction

Abstract

The water gas shift reaction plays a crucial role in the industrial upgrading of hydrogen sources. Here, xPtSm0.8Sr0.2CoO3/KIT-6 (x = 0.04, 0.18 and 0.51) was prepared via deposition-precipitation and polyvinyl alcohol-protected reduction method. Among all the samples, single atom Pt 0.04PtSm0.8Sr0.2CoO3/KIT-6 sample had the highest specific rate (10.99 molCO gPt-1 h-1) and turnover frequency (63.2Î10-2 s-1 at 250 °C), which was primarily attributed to the high valence of Pt single atom, high Oads/Olat molar ratio, and outstanding low-temperature reducibility. The DRIFTS demonstrated the redox mechanisms occur and carbonate as main intermediate over Pt single atom, while carboxylate and formate as intermediates by associative mechanisms over Pt nanoparticles. By DFT calculation, the adsorption energy of CO adsorbed over single atom Pt sample was much smaller than that over Pt nanoparticles. This work provides an effective approach to designing a high-performance catalyst for water gas shift reaction.

Keywords: Water gas shift, perovskite, Single atom catalysts, Pt.