A robust sandwich structural catalyst of (Cu/CuCo-MOF)2/MXene double heterojunction with outstanding activity toward hydrogen generation

• Published in: Applied catalysis. B, Environmental Environmental, 2024-12, Vol.358, p.124444, Article 124444
• Main Authors: Xu, Wenjing, Liu, Mei, Liu, Shuling, Guan, Shuyan, Zhang, Huanhuan, Shen, Ruofan, Wang, Yongfeng, Li, Baojun
• Format: Article
• Language: English
• Subjects: Ammonia borane; Bimetal; Double heterojunction; MXene; Synergistic effect
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2024.124444

Non-noble metal catalysts have exhibited promising prospects in ammonia borane (NH3BH3) hydrolysis, but their activity and stability still need to be further improved. Herein, a 2D sandwich heterostructural catalyst with Cu/CuCo-MOF and MXene-MOF double heterojunction has been prepared by coupling Ti3C2Tx MXene with bimetal organic framework nanosheets using a facile in situ growth strategy. The optimized CuCo-MOF/MX exhibits unprecedented activity with a turnover frequency (TOF) of 82.3 min–1 and excellent cycle stability, comparable to precious metal catalysts. Spectroscopic characterization and density functional theory (DFT) calculations reveal that Cu/CuCo-MOF heterojunction provides CuCo dual active sites for catalysis, and MXene-MOF heterojunction modulates the electronic structure and valence states of Cu sites via the Ti3C2Tx interlayer with 2D electron promoter effect to improve the synergistic effect of CuCo dual active sites. These modulation optimize the adsorption and dissociation of reactants, leading to a lower reaction barrier. This work provides insight into the 2D electron promoter effect, proposes a novel strategy for improving the performance of non-precious metal catalysts through constructing double heterojunction with 2D electron promoter effect. [Display omitted] •CuCo-MOF/MX with 2D sandwich heterostructures and double heterojunctions is prepared.•MXene optimizes the electronic structure and the synergy of dual active sites.•CuCo-MOF/MX catalyst shows high catalytic activity and stability.•The mechanism at CuCo-MOF/MX double heterojunction is proposed.