Biomass-derived N and P co-doped carbon-supported Pd catalyst for efficient CO2 hydrogenation to formate

CO 2 hydrogenation to formate is a crucial process for achieving carbon neutrality. A biomass-derived N and P co-doped carbon-supported Pd catalyst (Pd/CNP) was fabricated. N and P co-doping could enhance the catalytic performance by modulating Pd electron cloud density (the Pd 0 /(Pd 2+ +Pd 0 ) ratio), promoting Pd dispersion, and increasing the content of pyrrole-N, which promoted the dissociation of H 2 and the adsorption and activation of CO 2 . Due to the strong interaction between Pd and the heteroatoms of N and P, the Pd/CNP catalyst exhibited the highest catalytic activity (TON = 1655) in samples with different doping and pyrolysis temperatures. Kinetic analysis showed that Pd/CNP reduced the activation energy of CO 2 hydrogenation to formate compared with that of Pd/C. The kinetic equation of Pd/CNP is R’= k·M NEt3-CO2 0.65 ·P H2 1.21 (NEt 3 refers to triethylamine), and NEt 3 -CO 2 is a better choice of carbon source for hydrogenation than bicarbonate and CO 2 , which is obviously different from that of Pd/C catalyst.