Nanofibrous rhodium with a new morphology for the hydrogenation of CO2 to formate

Abstract

Herein, fibrous rhodium (Rh) was engineered using a microemulsion system. In this study, we report the design and synthesis of high-surface-area rhodium using Na₃RhCl₆. The fibrous rhodium nanocatalyst was thoroughly characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and a N₂ adsorption/desorption study. Due to the large ionic internal character, high mechanical and thermal stability as well as long-term colloidal stability, this system could be considered as a perfect nanocatalyst using the host–guest approach. Fibrous rhodium NPs were highly active for the catalytic hydrogenation of carbon dioxide with a 1 M KOH solution at 70 °C using 1 : 1 partial pressure of pCO₂/pH₂ and provided a high yield of 97% in 12 h; moreover, the influences of all the catalytic parameters and the reusability of the catalyst were investigated; the catalyst offers high activity and strong potential for application in the carbon dioxide reaction in aqueous media with an affordable metal source and molecular hydrogen.