Facet-dependent spatial separation of dual cocatalysts on MOF photocatalysts for H2O2 production coupling biomass oxidation with enhanced performance

• Published in: Applied catalysis. B, Environmental Environmental, 2025-05, Vol.364, p.124855, Article 124855
• Main Authors: Yuan, Ling, Du, Peiyang, Zhang, Chaoqi, Xi, Yamin, Zou, Yingying, Li, Jiaxin, Bi, Yin, Bao, Tong, Liu, Chao, Yu, Chengzhong
• Format: Article
• Language: English
• Subjects: Biomass oxidation; Crystal facet engineering; Metal-organic framework; Photocatalytic H2O2 production; Spatial charge separation
• ISSN: 0926-3373
• DOI: 10.1016/j.apcatb.2024.124855

Cooperative coupling of photocatalytic two-electron oxygen reduction reaction (2e-ORR) with oxidative organic synthesis holds great promise for sustainable production of valuable chemicals. To achieve high performance, the rational design of photocatalysts with effective electron-hole separation and redox capability is crucial. Herein, a MOF-based photocatalyst with crystal facet-dependent spatial separation of dual cocatalysts is constructed for photocatalytic 2e-ORR coupled with vanillyl alcohol oxidation reaction (VAOR). The facet-dependent growth of reductive Pd and oxidative CoOx cocatalysts respectively on the {100} and {001} facets of MIL-125-NH2 enables the directional migration of photogenerated carries, facilitating the charge separation for redox reactions. Additionally, the interaction between Pd and MIL-125-NH2 modulates the Pd sites into electron-sufficient state with upshifted d-band center, promoting the O2 activation and *OOH intermediate formation. The rationally designed composite photocatalyst delivers an excellent H2O2 yield of 74.8 mM g−1 h−1 and a high vanillic acid production rate of 80.9 mM h−1 g−1 with the conversion and selectivity of 96.8 % and 91.1 %, respectively. [Display omitted] •MOF-based photocatalysts with facet-dependent spatial separation of cocatalysts.•Directional migration of photogenerated carries facilitate the charge separation.•Coupling photocatalysis of H2O2 production and vanillyl alcohol oxidation reaction.•Remarkable H2O2 and vanillic acid yields of 74.8 and 80.9 mM h−1 g−1, respectively.