Lattice Hydroxyl-Assisted Platinum Single Atom Catalyst Toward Hydrogen Production From Methanol Aqueous Reforming.

Methanol aqueous reforming reaction (APRM) provides a green and clean route towards hydrogen production, in which the structure design and preparation of efficient catalysts remains a challenge. Herein, we report a platinum catalyst supported on the porous hydroxyl lanthanum oxide, which is prepared via glycine combustion method followed by a reduction process. The optimized 0.8%Pt/La catalyst, which is featured by Pt single-atom dispersed on a La2(OH)2 xO3-2 x support, exhibits an extraordinary catalytic performance towards APRM. A H2 production rate of 7672 µmolH2 gcat -1 min-1 and an average turnover frequency (ATOF) of 11973 h‒1 are obtained, which is preponderant to the state-of-the-art catalysts. An in-depth investigation based on kinetic isotope analysis, in situ spectroscopy characterizations and theoretical calculations substantiates that Pt single atom coordinated with adjacent lattice hydroxyl (OHL) with electron transfer from Pt to support serves as the intrinsic active site, in which the Ptδ + site promotes the dehydrogenation of methoxyl whilst lattice hydroxyl directly participates in the oxidative coupling process (CH2O* + OHL → CH2OOH*). Furthermore, the Ptδ +-(OHL)x-La interface sites can remarkably reduce the energy barrier of CH2OOH* dehydrogenation (rate-determining step), and the resulting hydroxyl vacancies can boost H2O dissociation to recover consumed OHL, accounting for the exceptional catalytic performance.