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Electrochemical reduction of CO 2 over wood-derived metal-free N-doped carbon electrocatalysts provides a new route for converting CO 2 into value-added fuels However, it is a challenge to efficiently design and screen high-performance electrocatalysts. In this paper, we combined the Marcus equation with the theory of thermal-kinetic correlation to successfully predict the optimal N-C doping ratio. Poplar wood -derived 3D N-doped graphitized carbon with optimal N doping content (pyridine-N 1.87 at%, pyrrole-N, 1.52 at%), high specific surface area (471.2 m2 g−1), and abundant nanopores were successfully obtained with the assistance of melamine (N source), which exhibited a high ECR activity of 86.78 % at a low applied potential of −0.71 V (vs. RHE) and long-term stability of at least 10 cycles. This extends the application of the Marcus equation and improves new ideas for the future design of high-performance electrocatalysts. [Display omitted] • "Thermodynamic-kinetic-N/C doping ratio" curve established. • The accuracy of the "thermodynamics-kinetics -N/C doping ratio" curve is verified. • PB-NC4 shows high industrial potential. [ABSTRACT FROM AUTHOR]

Summary: The production of CO via electrochemical CO2 reduction has been recognised as a promising technology that overcomes the environmental issues caused by global warming. It also facilitates the conversion of CO2 into energy sources. Earth‐abundant Zn is a well‐known alternative to noble metal catalysts such as Au and Ag for the electrochemical CO2 reduction to CO. In particular, Zn‐based materials in the form of nanowires are potentially applicable as electrocatalysts in the electrochemical CO2 reduction. However, the conventional methods for manufacturing the nanowire structure are difficult as they require harsh conditions such as high temperatures and excess energy. In this study, Zn‐based nanowire catalysts are prepared by the facile electrodeposition of Zn nanostructures on a substrate followed by their energy‐free solution‐phase reconstitution. Further, their electrochemical performance in the CO2 reduction is investigated in a CO2‐purged 0.5 M KHCO3 electrolyte. By optimising the deposition conditions, hexagonal Zn (h‐Zn) plates with dominant Zn(101) facets, the favoured crystal structure for CO2 reduction, are fabricated on carbon paper. Furthermore, it is found that, during the solution‐phase reconstruction over 16 hours, the h‐Zn plate transforms to a nanowire owing to the differences between the oxidation rates of different crystal facets and the formation of a hydroxide complex. The activity of the reconstructed Zn‐based nanowire catalyst is enhanced further by forming an oxide layer via thermal treatment in a H2 atmosphere. This treatment boosted the reaction kinetics, thereby enhancing the catalyst performance in the CO2 reduction. [ABSTRACT FROM AUTHOR]

This paper presents the experimental investigation of copper loaded carbon nanotubes (CNTs) electrocatalysts for the electrochemical reduction of carbon dioxide. The electrocatalysts were synthesized by homogeneous deposition precipitation method (HDP) using urea as precipitating agent. The prepared catalysts were characterized by TEM, SEM, XRD, XPS, BET, and FTIR for their morphology and structure. Characterization results confirm the deposition of Cu nanoparticles (3-60 nm) on CNTs. Linear sweep voltammetry (LSV) and chronoamperometry (CA) were used to investigate the activity of the as-prepared catalysts for the electrochemical reduction of carbon dioxide. The electrocatalysts reduced CO2 with high current density in the potential range 0~-3V versus SCE (standard calomel electrode). Among all catalysts tested, 20 wt. % copper loaded CNTs showed maximum activity. Gas chromatograph with TCD was used to analyze liquid phase composition. The faradaic efficiency for methanol formation was estimated to be 38.5%. [ABSTRACT FROM AUTHOR]