Tailoring ultrastable CuNiCs amorphous cluster via entropy engineering for acetylene selective hydrogenation

Alloying and phase separation of multimetallic catalysts induced by external environments are common phenomena. Understanding the structure–activity relationship of the deactivation process is crucial for tailoring highly stable active sites. Herein, characterization and long-term evaluation found that there are two main reasons for the deactivation of CuNi catalysts in acetylene selective hydrogenation: (1) Metal Ni segregation; (2) Carbon deposit. Inspired by this, we uses the high mixing entropy of multiple metals to induce the formation of CuNiCs amorphous clusters (ACs) with uniform size and dispersion. And electron transfer between Ni sites and adjacent sites (Cs and Cu) forms a rich electron-rich Ni sites which effectively reduces the adsorption difference energy of acetylene and ethylene on the catalysts surface. And E ads (C 2 H 2 )-E ads (C 2 H 4 ) can be used as a descriptor for ethylene selectivity. Finally, CuNiCs/TiO 2 ACs catalysts achieved the acetylene conversion of 99.1 % and the ethylene selectivity of 92.1 % at 180 °C, and showed no signs of deactivation after 110 h long-term evaluation.