Breaking the Activity-and-Selectivity Seesaw while Enhancing Heat Management via the Lattice Effect of a Single-Atom Alloy

When single-atom catalysts are oriented toward practical applications, in addition to balancing the seesaw between activity and selectivity, the capability of thermal management also merits attention. Herein, we proposed a facility approach that, based on active Pd in the state of a single atom, tunes the guest Cu size to simultaneously enhance the effect of d-electron domination and the heat transfer behavior in microregions. Along with the Cu size in an order of magnitude increase, more delocalized electrons were generated and transferred to isolated Pd sites, with the d band center shifting from 1.438 to 1.052 eV, closer to the Fermi level. Simultaneously, more long-range ordered lattices are much favorable for transferring in situ generated thermally phonons with the diffusivity surging from 12.36 to 103.49 mm²/s. The optimized Pd₁Cu-SAA catalyst exhibited state-of-the-art performance in acetylene hydrogenation, achieving full conversion at 140 °C, with 95.3% selectivity and good stability in the test period.