A Durable Nickel Single‐Atom Catalyst for Hydrogenation Reactions and Cellulose Valorization under Harsh Conditions. Issue 24 (9th May 2018)

• Record Type: Journal Article
• Authors: Liu, Wengang; Chen, Yinjuan; Qi, Haifeng; Zhang, Leilei; Yan, Wensheng; Liu, Xiaoyan; Yang, Xiaofeng; Miao, Shu; Wang, Wentao; Liu, Chenguang; Wang, Aiqin; Li, Jun; Zhang, Tao
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 24(2018)
• Page Start: 7071
• Page End: 7075
• Publication Date: 2018-05-09
• Subjects: active sites -- biomass conversion -- nickel -- single-atom catalysts -- XANES simulation; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201802231
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Hydrothermally stable, acid‐resistant nickel catalysts are highly desired in hydrogenation reactions, but such a catalyst remains absent owing to the inherent vulnerability of nickel under acidic conditions. An ultra‐durable Ni‐N‐C single‐atom catalyst (SAC) has now been developed that possesses a remarkable Ni content (7.5 wt %) required for practical usage. This SAC shows not only high activities for hydrogenation of various unsaturated substrates but also unprecedented durability for the one‐pot conversion of cellulose under very harsh conditions (245 °C, 60 bar H2, presence of tungstic acid in hot water). Using integrated spectroscopy characterization and computational modeling, the active site structure is identified as (Ni‐N4)⋅⋅⋅N, where significantly distorted octahedral coordination and pyridinic N constitute a frustrated Lewis pair for the heterolytic dissociation of dihydrogen, and the robust covalent chemical bonding between Ni and N atoms accounts for its ultrastability. Abstract : Ni‐N‐C SAC : A high‐loading (7.5 wt %) Ni single‐atom catalyst is developed for hydrogenation reactions and one‐pot conversion of cellulose to ethylene glycol under harsh hydrothermal conditions. The catalyst has a well‐defined active site with a significantly distorted structure in which the isolated Ni cation and the adjacent non‐coordinated pyridinic N atom constitute a frustrated Lewis pair (FLP) for heterolytic dissociation of dihydrogen.