Accelerated Oxygen Dual Activation and Acetic Acid Activation for Hydrogen Production via Autothermal Reforming of Acetic Acid

Catalytic conversion of the biomass-derived secondary product, namely, autothermal reforming of acetic acid (HAc), into hydrogen offers a potential route to alleviate current energy problems. Hitherto, the precise activation of oxygen species, including lattice O2– and molecular O2, has not been achieved, which restrains the oxygen catalytic cycle and carbon precursor gasification. Herein, Sm–Ce–O solid solution (SC)-supported dual-site Ni (single atom (SA) + nanoparticle (NP)) catalysts were obtained. The redox couples of Sm2+/Sm3+ and Ce3+/Ce4+ induced support lattice distortion, which facilitated lattice O2– activation. Simultaneously, the abundant oxygen vacancies near the nickel single atom sites accelerated the chemisorption and activation of molecular O2. Furthermore, the constructed NiSA-SC interface promoted migration of subsurface lattice O2– to the surface, which in turn was supplemented by molecular O2. Although with higher oxygen activation ability, the poor reactivity in adsorption and C–C bond breaking of CH3CO* for the NiSA-SC interface led to undesirable HAc conversion, which could be improved by introducing the NiNP-SC interface. Consequently, with the NiSA-SC interface and solid solution activated molecular O2 and lattice O2–, respectively, and the NiNP-SC interface promoted HAc conversion, the optimal Ni0.32Sm0.88Ce0.12O1.88 ± δ catalyst with dual-site Ni ran for 10 h without deactivation and exhibited a high hydrogen yield of 2.6 mol-H2/mol-HAc.