Thermal effect optimization endows a selective and stable PdCu single atom alloy catalyst for acetylene hydrogenation

Here, we proposed a universal approach to solve a seesaw relationship between thermal effect control and conversion efficiency in strong exothermic acetylene hydrogenation by constructing Pd‐based single atom alloy (SAA), in which Cu was chosen as host atom and heat transfer agent. Lower desorption energy of *C 2 H 4 intermediate on isolated Pd atoms greatly improved ethylene selectivity. Notably, this excellent performance was well maintained, even at extremely low space velocity, implying the thermal effect was effectively controlled. On one hand, the heat generation rate over single active site was largely decreased. On another hand, host Cu atoms with proper continuity degree endowed the SAA with attractive lattice heat capacity and phonon scattering rate, which ensured the instant heat transfer from Pd atoms to the surroundings. The optimized performance (conversion 90.7% and selectivity 95.8%) was stably operated for 270 h under GHSV = 2400 h −1 .