Enhancing Low-Temperature Syngas Production via Surface Tailoring of Supported Intermetallic Nanocatalysts

Abstract

An active and coke-resistant silica-encapsulated intermetallic Ni 3 Zn nanoparticle catalyst was developed for low-temperature (450 °C) dry reforming of methane (DRM). The catalyst exhibited a remarkable 4-fold increase in activity (4.5 s −1 ) with over 99% CO selectivity and 3 orders of magnitude less carbonaceous species and demonstrated remarkable stability (70 h) compared to that of a monometallic Ni catalyst. The key is the combined effect of surface ensemble structure and electronic interaction modulation through the surface composition tailoring achieved by offstoichiometric Ni and Zn loading in controlling surface chemistry for achieving different activities and H 2 /CO ratios. Characterized by ion spectroscopy, X-ray photoelectron spectroscopy, and the neutron pair distribution function, it was revealed that paired Ni δ− −Zn δ+ active sites are crucial for DRM. Transient infrared spectroscopy and isotopic analysis uncovered the synergistic effect of Ni δ− −Zn δ+ sites in activating C−H bonds and dissociating CO 2 to prevent coke formation under low-temperature conditions.