Modulating the Acidic Properties of Mesoporous Mo<sub>x</sub>–Ni<sub>0.8</sub>Cu<sub>0.2</sub>O Nanowires for Enhanced Catalytic Performance toward the Methanolysis of Ammonia Borane for Hydrogen Production
Yufa Feng, Xuefeng Zhang, Youxiang Shao, Xiaodong Chen, Huize Wang, Junhao Li, Ming Wu, Huafeng Dong, Quanbing Liu, Hao Li
Abstract
Rational construction of inexpensive, highly efficient, and stable catalysts for ammonia borane (AB) methanolysis is in high demand but still remains a great challenge. In this work, we have successfully fabricated uniform Mo x –Ni 0.8 Cu 0.2 O nanowires using a simple hydrothermal method followed by a post-calcination treatment and flexibly modulated the acidity of their surface by changing the amount of Mo introduced into Ni 0.8 Cu 0.2 O. The Mo 0.1 –Ni 0.8 Cu 0.2 O catalyst displayed strong catalytic activity toward AB methanolysis with an ultrahigh turnover frequency of 46.9 mol H 2 mol cat. –1 min –1, which is even higher than some noble metal catalysts. In this work, an equation regarding the relationship between the quantity of moderated acid sites of catalysts and its corresponding activity toward AB methanolysis was first determined. A plausible mechanism for AB methanolysis catalyzed by Mo x –Ni 0.8 Cu 0.2 O was proposed, and the benefits of the introduction of MoO 3 to Ni 0.8 Cu 0.2 O for enhancing the catalytic performance were also discussed. These findings can form a basis for the rational construction of inexpensive catalysts with robust performance toward AB methanolysis for hydrogen production.