Efficient Electrochemical Reduction of Carbon Dioxide to Acetate on Nitrogen-Doped Nanodiamond

Abstract

Electrochemical reduction of CO2 is an attractive technique for reducing CO2 emission and converting it into useful chemicals, but it suffers from high overpotential, low efficiency or poor product selectivity. Here, N-doped nanodiamond/Si rod array (NDD/Si RA) was proposed as an efficient nonmetallic electrocatalyst for CO2 reduction. It preferentially and rapidly converted CO2 to acetate over formate with an onset potential of -0.36 V (vs RHE), overcoming the usual limitation of low selectivity for C2 products. Moreover, faradic efficiency of 91.2-91.8% has been achieved for CO2 reduction at -0.8 to -1.0 V. Its superior performance for CO2 reduction can be attributed to its high overpotential for hydrogen evolution and N doping, where N-sp(3)C species was highly active for CO2 reduction. Electrokinetic data and in situ infrared spectrum revealed the main pathway for CO2 reduction might be CO2 → CO2(•-) → (COO)2(•) → CH3COO(-).

CO2 Reduction: From the Electrochemical to Photochemical Approach

“…In addition, C 2 –C 3 products are also obtained. Quan and co‐workers observed that N‐doped nanodiamond (NDD) demonstrated Faradaic efficiency of ≈77% toward acetate production and ≈15% toward formate formation at a potential range of −0.8–−1 V versus RHE 109. It was the first example of CO 2 RR electrocatalysts other than Cu that were able to convert CO 2 to a C 2 product with such high selectivity.…”

Carbon Solving Carbon's Problems: Recent Progress of Nanostructured Carbon‐Based Catalysts for the Electrochemical Reduction of CO2

“…In an effort to introduce CO 2 RR active sites with low onset potentials, doping of boron and nitrogen into nanodiamond materials has recently been studied for CO 2 RR application. [92,93] As shown in Figure 8a, N-doped nanodiamond (NDD) was deposited on a silicon rod array using a microwave plasma enhanced CVD method and applied directly as an electrocatalyst for CO 2 reduction. [92] The CO 2 RR onset potential was -0.36 V vs RHE and it was found that the NDD could preferentially produce acetate under any applied potential within the CO 2 RR potential range.…”

Carbon-Based Metal-Free Electrocatalysis for Energy Conversion, Energy Storage, and Environmental Protection

“…In this context, carbon-based metal-free catalysts have also been used for CO 2 RR. Figure 11 and Table 1 represent recent advances in the development of carbon-based metal-free catalysts for CO 2 RR [36,37,[207][208][209][210][211][212][213][214].…”

“…Because C2 products are more valuable than C1 products, the development of efficient carbon electrocatalysts for the reduction of CO 2 to C2 products is highly desirable. N-doped diamonds (NDD) can serve as promising electrocatalysts for CO 2 reduction to not only C1 products (formate), but also C2 products (acetate) with high efficiency, fast kinetics, and good selectivity [209]. The higher production rates for acetate than formate on NDD catalysts indicate that C-C coupling preferentially occurs at the initial stage of CO 2 RR.…”