Metal-base bifunctional Ni catalyst for enhancement of hydrogen production by aqueous phase reforming of methanol

Aqueous phase reforming of methanol (APRM) for on-site hydrogen production is a very promising energy alternative, but the lack of high-efficiency catalysts hinders its rapid improvement. Herein, we have prepared layered double hydroxide derived metal-base bifunctional Ni catalysts that exhibit excellent catalytic performance in APRM. The hydrogen production rate and turnover frequency of the optimal catalyst Ni 2 Mg 1 -MMO-1 are 285.2 μmol H2 /g cat. /s and 2094 h −1 at 240 °C, respectively, exceeding the best result reported so far for Ni-based catalysts. Characterization results reveal that the more Ni 0 and base sites present on the catalyst surface, the better performance tends to be achieved. The reaction mechanism is investigated by TPSR and in situ DRIFTS techniques. A possible pathway, methanol dehydrogenation and water–gas shift (WGS), is proposed. Notably, the WGS stage undergoes an associative mechanism, where water is efficiently activated at base sites and bonds with CO adsorbed on Ni 0 sites to form formate, which is the key to enhancing hydrogen production in APRM.