Noble Metal-Free 2D 1T-MoS₂ Edge Sites Boosting Selective Hydrogenation of Maleic Anhydride

Abstract

Layered two-dimensional (2D) materials have attracted enormous attention as appealing catalysts and supports for various electro- and photocatalytic transformations. Here, we report another unique behavior of 2D MoS2 for heterogeneous selective hydrogenation, which exhibits excellent activity (100%) and selectivity (100%) for industrially important maleic anhydride (MAH) hydrogenation to succinic anhydride (SA), comparable to the cutting-edge commercial noble-metal catalysts. The specific reaction rate increases linearly with the concentration of 1T-phase MoS2, confirming the excellent intrinsic activity of 1T-MoS2 for MAH to SA. The electron-rich Mo sites on the oxidized Mo edges of 1T-MoS2 form a pocketlike active site (HO–Mo–S–Mo–S–Mo–OH), which confines the MAH adsorption mode due to the steric effect and further promotes H2 activation due to the itinerant electrons of Mo4+ in 1T-MoS2. The strategy of constructing edge-confined active centers with specific phase composition of 2D materials opens an approach to developing highly efficient catalysts for chemical transformations.