Ambient-condition acetylene hydrogenation to ethylene over WS-confined atomic Pd sites.

Ambient-condition acetylene hydrogenation to ethylene (AC-AHE) is a promising process for ethylene production with minimal additional energy input, yet remains a great challenge due to the difficulty in the coactivation of acetylene and H at room temperature. Herein, we report a highly efficient AC-AHE process over robust sulfur-confined atomic Pd species on tungsten sulfide surface. The catalyst exhibits over 99% acetylene conversion with a high ethylene selectivity of 70% at 25 C, and a record space-time yield of ethylene of 1123 mol mol h under ambient conditions, which is nearly four times that of the typical PdAg/AlO catalyst, and exhibiting superior stability of over 500 h. We demonstrate that the confinement of Pd-S coordination induces positively-charged atomic Pd, which not only facilitates CH hydrogenation but also promotes CH desorption, thereby enabling a high conversion of CH to CH at room temperature while suppressing over-hydrogenation to CH.