Promoted oxygen vacancy formation by highly dispersed Pd single atoms anchored on SBA-15 decorated La0.5Ca0.5MnO3 for efficient water gas shift reaction

The dissociation of water is essential to water gas shift (WGS) reaction, and the presence of oxygen vacancies can facilitate this key step. Herein, a series of perovskite supported Pd single atoms catalysts were prepared via deposition precipitation method. The incorporation of Pd single atoms can effectively promote the formation of oxygen vacancy on the surface of the catalyst, improving the low temperature reducibility, the ratio of Mn 4 + /Mn 3+ and O ads /O lat compared with support. Among all samples, 0.82 Pd/La 0.5 Ca 0.5 MnO 3 /SBA-15 with the most oxygen vacancies presented 83.6 % CO conversion at 400 °C, specific reaction rate (0.54 mol CO g Pd −1 h −1 ), and TOF (3.77✕10 −2 s −1 ). DFT calculation proved that Pd doping can effectively decreased energy barrier of H 2 O dissociation, and promoted the formation of oxygen vacancies. This work provides experimental and theoretical insights into the rational design of highly active perovskite supported Pd single atom catalysts for WGS reaction.