Shi Yuchuan, Zhang Kaini, Dong Chung-Li, Nga Ta Thi Thuy, Wang Miao, Wei Daixing, Wang Jialin, Wang Yiqing, Shen Shaohua
International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Department of Physics, Tamkang University, New Taipei City 25137, China.
Sci Bull (Beijing). 2024 Aug 15;69(15):2395-2404. doi: 10.1016/j.scib.2024.06.014. Epub 2024 Jun 15.
Highly selective production of value-added multicarbon (C) products via electrochemical CO reduction reaction (eCORR) on polycrystalline copper (Cu) remains challenging. Herein, the facile surface modification using poly (α-ethyl cyanoacrylate) (PECA) is presented to greatly enhance the C selectivity for eCORR over polycrystalline Cu, with Faradaic efficiency (FE) towards C products increased from 30.1% for the Cu electrode to 72.6% for the obtained Cu-PECA electrode at -1.1 V vs. reversible hydrogen electrode (RHE). Given the well-determined FEs towards C products, the partial current densities for C production could be estimated to be -145.4 mA cm for the Cu-PECA electrode at -0.9 V vs. RHE in a homemade flow cell. In-situ spectral characterizations and theoretical calculations reveal that PECA featured with electron-accepting -C≡N and -COOR groups decorated onto the Cu electrode could inhibit the adsorption of *H intermediates and stabilize the *CO intermediates, given the redistributed interfacial electron density and the raised energy level of d-band center (E) of Cu active sites, thus facilitating the C-C coupling and then the C selective production. This study is believed to be guidable to the modification of electrocatalysts and electrodes with polymers to steer the surface adsorption behaviors of reaction intermediates to realize practical eCORR towards value-added C products with high activity and selectivity.
通过在多晶铜（Cu）上进行电化学CO还原反应（eCORR）来高选择性地生产增值多碳（C）产物仍然具有挑战性。在此，本文提出了使用聚（α-氰基丙烯酸乙酯）（PECA）进行简便的表面改性，以大大提高多晶Cu上eCORR的C选择性，在相对于可逆氢电极（RHE）为-1.1 V时，生成C产物的法拉第效率（FE）从Cu电极的30.1%提高到所得Cu-PECA电极的72.6%。考虑到生成C产物的FE已确定，在自制的流动池中，相对于RHE为-0.9 V时，Cu-PECA电极生成C的部分电流密度估计为-145.4 mA cm。原位光谱表征和理论计算表明，装饰在Cu电极上的具有吸电子-C≡N和-COOR基团的PECA可以抑制H中间体的吸附并稳定CO中间体，这是由于界面电子密度重新分布以及Cu活性位点的d带中心（E）能级升高，从而促进C-C偶联进而实现C的选择性生成。这项研究被认为对用聚合物修饰电催化剂和电极以控制反应中间体的表面吸附行为，从而实现具有高活性和选择性的实用eCORR以生成增值C产物具有指导意义。
