B-Doped Fullerene as a Potential Metal-Free Catalyst Material for CO Reduction Reaction

Reducing carbon monoxide (CO) plays an essential role in the goal of C1 chemistry. This study aims to design and develop B-doped fullerenes as the electrocatalyst for the CO reduction reaction using first-principles calculations based on density functional theory. The computational hydrogen electrode model has been employed to evaluate the catalytic properties of B-doped fullerene. It has been confirmed that the CO molecule adsorbs stably on C59B with an adsorption energy of -0.35 eV. When an external voltage of 0.39 V, the overvoltage, is applied, all reactions proceed downhill, selectively producing methane in an acidic environment. This value is sufficiently lower than previously reported values on metal surfaces. The reaction process to determine the overvoltage is the initial hydrogenation process, *CO -> *CHO. On the other hand, the CO molecule does not adsorb on a flat B-doped graphene nanocluster, implying that the curvature of the carbon network plays an important role in CO adsorption. Thus, we have investigated the dependence of the radius of the curvature on the adsorption energy and the overvoltage using a different size of fullerene, C69B. The reaction site with a radius of curvature of 4.86 & Aring; for C69B has a minimum overvoltage of 0.26 V. However, the adsorption energy of CO molecules is -0.12 eV, higher than that of C59B. This suggests the existence of an optimal radius of curvature for various applications. The curvature of the fullerene surface plays an important role as a catalyst for the CO reduction. This research will pave the way for developing catalytic properties of surfaces with curvature.