Stabilizing Ni-CeO<sub><i>x</i></sub> Bifunctional\nNanoparticles on Activated Alumina to Enhance Carbon Resistance for\nDry Reforming of Methane

Syngas, an extremely meaningful chemical feedstock consisting\nof\nhydrogen and carbon monoxide, can be produced through methane dry\nreforming with carbon dioxide. The extensively utilized Ni-based catalysts\nusually suffer from coke-induced instability. Herein, we design Ni-CeO<sub><i>x</i></sub> bifunctional catalysts with different proximity\nand explore the influence of proximity level on anticoking performance.\nNi-CeO<sub><i>x</i></sub> bimetallic nanoparticles with\nintimate contact are precisely regulated through the anchoring strategy\nof coordination unsaturated Al<sup>3+</sup><sub>penta</sub>, which\nundergoes the topotactic exsolution of a Ni–Ce–O quasi-solid\nsolution into Ni-CeO<sub><i>x</i></sub> bimetallic nanoparticles.\nA trend toward easier elimination and even the absence of graphitic\ncarbon is observed with a decreasing spatial distance between Ni and\nCeO<sub><i>x</i></sub>, which is attributed to the proximity\nbetween the dissociation and gasification sites of CH<sub><i>x</i></sub>* intermediates. CH<sub><i>x</i></sub>*\nspecies generated at Ni nanoparticles migrated to adjacent CeO<sub><i>x</i></sub> oxygen carriers for Ni-CeO<sub><i>x</i></sub>/Al<sub>2</sub>O<sub>3</sub> catalyst gasification with Ni-CeO<sub><i>x</i></sub> bimetallic nanoparticle interfaces, which\nundergo the Mars–van Krevelen (MvK) mechanism. The exploration\nof the Ni-CeO<sub><i>x</i></sub> proximity provides guidance\nfor developing efficient and durable Ni-based DRM catalysts.