Revamping SiO<sub>2</sub> Spheres by Core–Shell Porosity Endowment to Construct a Mazelike Nanoreactor for Enhanced Catalysis in CO<sub>2</sub> Hydrogenation to Methanol
Mohammadreza Kosari, Uzma Anjum, Shibo Xi, Alvin M. H. Lim, Abdul Majeed Seayad, Emmanuel A. J. Raj, Sergey M. Kozlov, Armando Borgna, Hua Chun Zeng
Abstract
Abstract Beyond the catalytic activity of nanocatalysts, the support with architectural design and explicit boundary could also promote the overall performance through improving the diffusion process, highlighting additional support for the morphology‐dependent activity. To delineate this, herein, a novel mazelike‐reactor framework, namely multi‐voids mesoporous silica sphere (MV m SiO 2 ), is carved through a top‐down approach by endowing core‐shell porosity premade Stöber SiO 2 spheres. The precisely‐engineered MV m SiO 2 with peripheral one‐dimensional pores in the shell and interconnecting compartmented voids in the core region is simulated to prove combined hierarchical and structural superiority over its analogous counterparts. Supported with CuZn‐based alloys, mazelike MV m SiO 2 nanoreactor experimentally demonstrated its expected workability in model gas‐phase CO 2 hydrogenation reaction where enhanced CO 2 activity, good methanol yield, and more importantly, a prolonged stable performance are realized. While tuning the nanoreactor composition besides morphology optimization could further increase the catalytic performance, it is accentuated that the morphological architecture of support further boosts the reaction performance apart from comprehensive compositional optimization. In addition to the found morphological restraints and size‐confinement effects imposed by MV m SiO 2 , active sites of catalysts are also investigated by exploring the size difference of the confined CuZn alloy nanoparticles in CO 2 hydrogenation employing both in‐situ experimental characterizations and density functional theory calculations.