Metal-support interaction triggered d-p orbital hybridization for efficient electrocatalytic semi-hydrogenation of alkynes

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2024-05, Vol.12 (19), p.11625-11634
• Main Authors: Wan, Qiong, Zhang, Jiaxun, Liu, Xuan, Li, Huizhi, Abdullah, Ren, Taotao, Liu, Qiyuan, Xu, Yongheng, Liu, Jia, Liu, Jicheng, Yao, Bingqing, Fang, Yiyun, Li, Xinzhe, He, Chi
• Format: Article
• Language: English
• Subjects: Alkenes; Alkynes; Ambient temperature; Atomic structure; Catalysts; Electrochemistry; Ferric oxide; Hybridization; Hydrogen; Hydrogenation; Intermediates; Nanoparticles; Palladium
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d4ta01240b

Semi-hydrogenation of alkynes to alkenes using electrochemical approaches is an appealing alternative to conventional thermocatalytic strategies, as it efficiently utilizes water as the hydrogen source at ambient temperature. However, the precise modulation of atomic and electronic structures of catalytic Pd active sites remains a persistent challenge, particularly in enhancing the conversion yield of alkynes and improving the selectivity of alkenes. Here, we synthesize Pd nanoparticles anchored onto the surface of the defective two-dimensional Fe 2 O 3 support, referred to as Pd/Fe 2 O 3 catalysts, to conduct the electrocatalytic semi-hydrogenation of alkynes. Intriguingly, we observed the reconstruction of the atomic structure and configuration of Pd nanoparticles in the Pd/Fe 2 O 3 catalysts due to metal-support interaction, caused by the hybridization of Pd d and O p orbitals. This interaction significantly weakens the binding strength of Pd sites in the Pd/Fe 2 O 3 catalysts to the chemisorbed 4-aminophenylacetylene and reactive hydrogen intermediates. Consequently, Pd/Fe 2 O 3 catalysts achieve a high conversion rate (99%) and selectivity (99%) in the semi-hydrogenation of 4-aminophenylacetylene coupled with high faradaic efficiency, outperforming both benchmark commercial Pd/C and other reference catalysts. Additionally, terminal alkynes featuring diverse functionalized groups, including those with easily reducible or passivated functionalities, can be efficiently semi-hydrogenated using Pd/Fe 2 O 3 catalysts. Atomic restructuring in Pd/Fe 2 O 3 catalysts weakens Pd binding to chemisorbed 4-aminophenylacetylene and hydrogen intermediates, boosting conversion and selectivity in 4-aminophenylacetylene semi-hydrogenation, surpassing Pd/C and other catalysts.