Highly Efficient and Selective CO₂Electro‐Reduction to HCOOH on Sn Particle‐Decorated Polymeric Carbon Nitride

Abstract

Electrochemical conversion of CO 2 into liquid fuels by efficient and earth-abundant catalysts is of broad interest but remains a great challenge in renewable energy production and environmental remediation. Herein, a Sn particle-decorated polymeric carbon nitride (CN) electrocatalyst was successfully developed for efficient, durable, and highly selective CO 2 reduction to formic acid. High-resolution X-ray photoelectron spectroscopy confirmed that the metallic Sn particles and CN matrix are bound by strong chemical interaction, rendering the composite catalyst a stable structure. More notably, the electronic structure of Sn was well tuned to be highly electron-rich due to the electron transfer from N atoms of CN to Sn atoms via metalsupport interactions, which favored the adsorption and activation of CO 2 molecules, promoted charge transport, and thus enhanced the electrochemical conversion of CO 2. The composite electrocatalyst demonstrated an excellent Faradaic efficiency of formic acid (FE HCOOH) up to 96 � 2 % at the potential of À 0.9 V vs. reversible hydrogen electrode, which remained at above 92 % during the electrochemical reaction of 10 h, indicating that the present Sn particle-decorated polymeric carbon nitride electrocatalyst is among the best in comparison with reported Sn-based electrocatalysts.

Unveiling the Synergistic Effect between Graphitic Carbon Nitride and Cu2O toward CO2Electroreduction to C2H4

“…As depicted in Figure 2b, only C, N, Cu and O elements are detected in full X‐ray photoelectron spectroscopy (XPS) survey, [14] indicating that no other impurity elements are present. From the high‐resolution N 1 s spectra of the Cu 2 O/CN shown in Figure 2c, four peaks at 398.4, 399.6, 400.8 and 404.0 eV are corresponding to four different types of N‐binding modes, that is, sp 2 ‐bonded N (C−N=C), tertiary nitrogen [N−(C) 3 ], quaternary‐N (N−H) and π‐excitation, respectively, [10,15] which is consistent with the N 1s spectra of CN. As shown in Table S1, the ratio of different types of N in each sample is calculated by the geometric area of the corresponding peak of different N species in N 1 s spectra.…”

“…When metal and its oxide are difficult to volatilize at high temperatures, thermogravimetric analysis (TGA) can be used to effectively analyze the content of each component in the metal/carbon system [15] . As shown in Figure S4, the thermogravimetric curve indicates that the oxidation process of cuprous oxide began at about 573 K, which caused a little increase of the weight.…”

Engineering Sn‐based Catalytic Materials for Efficient Electrochemical CO2 Reduction to Formate

“…Copyright 2020 IOP Publishing. (b) Faradaic efficiency of HCOOH on Sn/Graphitic Carbon Nitride with different NaBH 4 solution concentration (0.05 M, 0.1 M and 0.2 M) vs applied potential done in a 0.1 M KHCO 3 pH 6.8 electrolyte [79] . Reproduced with permission from Ref.…”

“…fabricated Sn on graphitic carbon nitride and achieved a formate FE of 96% at −0.9 V RHE (Figure 6b) . [79] This is achieved through the charge transfer from N in the support to Sn, resulting in an electron‐rich Sn which promotes adsorption and activation of CO 2 .…”

Oxidative Conversion of Glucose to Formic Acid as a Renewable Hydrogen Source Using an Abundant Solid Base Catalyst

“…[11,12] Formic acid is one of the most promising hydrogen carriers. [13,14] It can be produced from saccharides by selective oxidation [15][16][17][18][19] or carbon dioxide transformation, including catalytic hydrogenation, [20][21][22] electrochemical reduction, [23,24] and photocatalytic reduction. [25][26][27] In the former case, formic acid is obtained from monosaccharides regardless of the type, such as glucose, xylose, and mannose.…”