GaN Nanowire-Supported NiOx for Low-Temperature and Durable Dry Reforming of Methane toward Syngas

Dry reforming of methane toward syngas (CH 4 + CO 2 = 2CO + 2H 2 ) presents a proper solution for depleting petroleum and climate change yet remains not industrialized. Herein, NiO x nanoparticles are coupled with GaN nanowires for this target. The as-designed hybrid of NiO x /GaN NWs demonstrates a low onset temperature of 280   o C for dry reforming of methane with a syngas activity of 121.7   mmol·g cat -1 ·h -1 and nearly 100% selectivity. Together with the outstanding stability, a turnover number of 40372 mole syngas per mole Ni species is achieved over 160 cycles without noticeable activity degradation. The correlative kinetic experiments, isotope experiments, in-situ spectroscopic characterizations, as well as density functional theory calculations reveal that the oxidized nickel species with O vacancies and its unique electronic interaction with GaN significantly reduce the apparent activation energy of the reaction, primarily contributing to the superior activity at low temperature. What is more, the evolution track of CH 4 and CO 2 to syngas was comprehensively studied at atomic level, disclosing an obvious anti-coking chemical loop with excellent stability. This work presents a strategy for efficient and stable dry reforming of methane toward syngas under mild conditions.