Title: Unraveling the role of substrate materials in governing the carbon/carbide growth of molten carbonate electrolysis of CO₂

Author(s): Yu, R (Yu, Rui); Du, KF (Du, Kaifa); Deng, BW (Deng, Bowen); Yin, HY (Yin, Huayi); Wang, DH (Wang, Dihua)

Source: NANOSCALE  Volume: 15  Issue: 46  Pages: 18707-18715  DOI: 10.1039/d3nr03702a  Early Access Date: SEP 2023   Published: NOV 30 2023  

Abstract: The interface interaction between deposited carbon and metallic electrode substrates in tuning the growth of CO2-derived products (e.g., amorphous carbon, graphite, carbide) is mostly unexplored for the high-temperature molten-salt electrolysis of CO2. Herein, the carbon deposition on different transition-metal cathodes was performed to reveal the role of substrate materials in the growth of cathodic products. At the initial stage of electrolysis, transition metals (e.g., Cr, Fe, Ni, and Co) that exhibit appropriate carbon-binding ability (in range of -30 to 60 kJ mol(-1)) allow carbon diffusing into and then dissociating from metal to form graphite, as the carbon-binding ability can be determined by the Gibbs free energy of formation of metallic carbides. The catalytic cathodes showing super strong (e.g., Ti, V, Mo, and W) or weak (e.g., Cu) carbon-binding ability produce stable carbides or amorphous carbon, respectively. However, the subsequent deposited carbon is immune to the catalysis of the substrate, forming amorphous carbon nanoparticles and nanofibers on the surface of carbides and graphite, respectively. This paper not only highlights the role of the catalytic cathodes for carbon deposition, but also offers a material selection principle for the controllable growth of CO2-derived products in molten salts.

PubMed ID: 37953684

Addresses: [Yu, Rui; Du, Kaifa; Deng, Bowen; Yin, Huayi; Wang, Dihua] Wuhan Univ, Sch Resource & Environm Sci, Hubei Int Sci & Technol Cooperat Base Sustainable, Wuhan 430072, Peoples R China.

Corresponding Address: Du, KF; Wang, DH (corresponding author), Wuhan Univ, Sch Resource & Environm Sci, Hubei Int Sci & Technol Cooperat Base Sustainable, Wuhan 430072, Peoples R China.

邮箱地址: dukf@whu.edu.cn; wangdh@whu.edu.cn

影响因子：6.7