Insight into the Active Sites of N,P-Codoped Carbon Materials for Electrocatalytic CO₂ Reduction

Abstract

Doping heteroatoms in carbon materials is a promising method to prepare the robust electrocatalysts for the carbon dioxide reduction reaction (CO2RR), which is beneficial for sustainable energy storage and environmental remediation. However, the obscure recognition of active sites is the obstacle for further development of high-efficiency electrocatalysts, especially for the N,P-codoped carbon materials. Herein, a series of N,P-codoped carbon materials (CNP) is prepared with different N and P contents to explore the relationship between the N/P configuration and the CO2RR activity. As compared with the N-doped carbon materials, the additional P doping is helpful to improve the activity. The optimum N,P-codoped carbon materials (CNP-900) achieve 80.8% CO Faradaic efficiency (FECO) at a mild overpotential of 0.44 V. On the basis of the X-ray photoelectron spectroscopy results, the suitable ratio between pyridinic N and graphitic N and the least P–N content are beneficial for CO2RR. The density functional theory calculations further illustrate that two elementary steps to form *COOH and *CO in CO2RR are determined by the graphitic N and pyridinic N configurations, respectively. The existence of the P–N configuration breaks the equilibrium between graphitic N and pyridinic N to suppress the activity.

Electrochemical reduction of carbon dioxide to multicarbon (C2+) products: challenges and perspectives

“…116,117 Moreover, the intrinsic physicochemical properties of carbon supports can be regulated using doping and surface functionalization, thus improving the total charge and increasing CO 2 concentration on the electrode surface. 118…”

“…116,117 Moreover, the intrinsic physicochemical properties of carbon supports can be regulated using doping and surface functionalization, thus improving the total charge and increasing CO 2 concentration on the electrode surface. 118 Zhou and colleagues have theoretically investigated the activity and selectivity of metal trimer clusters anchored on N-doped carbon supports to form C 2 -C 3 hydrocarbons and alcohols (Fig. 7A).…”

Efficient Selective Catalytic Fixation of CO2 into Epoxide to Form Cyclic Carbonates Using Sodium Aluminate Engineered Gamma Alumina Catalyst

“…10,11 Cyclic carbonate compounds find extensive use in various eminent fields, serving as components of surfactants/emulsifiers, solvents, electrolytes, and are predominantly applicable in pharmaceuticals, agrochemicals, Li-ion batteries, cosmetics, and more. [12][13][14] Till today, for cyclic carbonates synthesis, few efficient non-recyclable and recyclable catalysts were reported, such as DBU, 15 ILs, 16 ligand-based catalysts, 17 organocatalysts, 18 metal complexes, 19,20 metal/mixed metal oxides, 21,22 covalent organic frameworks (COFs), 23 metal organic frameworks (MOFs), 1 porous organic polymers (POPs), 8,24 silica-based oxides, 25 carbon-supported oxides, 26,27 and so on. However, earlier reported catalysts are suffering from a few drawbacks, such as a tedious catalyst synthesis procedure, use of hazardous chemicals, a long reaction time, less stability, less catalytic activity, harsh reaction conditions, recovery, and recyclability.…”