Abstract
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(2) 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 (o)C, and a record space-time yield of ethylene of 1123 mol(C2H4) mol(Pd)(-1) h(-1) under ambient conditions, which is nearly four times that of the typical Pd(1)Ag(3)/Al(2)O(3) catalyst, and exhibiting superior stability of over 500 h. We demonstrate that the confinement of Pd-S coordination induces positively-charged atomic Pd(δ+), which not only facilitates C(2)H(2) hydrogenation but also promotes C(2)H(4) desorption, thereby enabling a high conversion of C(2)H(2) to C(2)H(4) at room temperature while suppressing over-hydrogenation to C(2)H(6).