Lawrence Matthew J, Celorrio Veronica, Sargeant Elizabeth, Huang Haoliang, Rodríguez-López Joaquín, Zhu Yuanmin, Gu Meng, Russell Andrea E, Rodriguez Paramaconi
School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
Diamond Light Source Ltd, Diamond House, Harwell Campus, Didcot OX11 0DE, U.K.
ACS Appl Mater Interfaces. 2022 Jan 19;14(2):2742-2753. doi: 10.1021/acsami.1c19298. Epub 2022 Jan 4.
The electrochemical conversion of carbon dioxide (CO) to useful chemical fuels is a promising route toward the achievement of carbon neutral and carbon negative energy technologies. Copper (Cu)- and Cu oxide-derived surfaces are known to electrochemically convert CO to high-value and energy-dense products. However, the nature and stability of oxidized Cu species under reaction conditions are the subject of much debate in the literature. Herein, we present the synthesis and characterization of copper-titanate nanocatalysts, with discrete Cu-O coordination environments, for the electrochemical CO reduction reaction (CORR). We employ real-time in situ X-ray absorption spectroscopy (XAS) to monitor Cu species under neutral-pH CORR conditions. Combination of voltammetry and on-line electrochemical mass spectrometry with XAS results demonstrates that the titanate motif promotes the retention of oxidized Cu species under reducing conditions for extended periods, without itself possessing any CORR activity. Additionally, we demonstrate that the specific nature of the Cu-O environment and the size of the catalyst dictate the long-term stability of the oxidized Cu species and, subsequently, the product selectivity.
将二氧化碳(CO₂)电化学转化为有用的化学燃料是实现碳中性和碳负性能源技术的一条有前景的途径。已知铜(Cu)及其氧化物衍生的表面能将CO₂电化学转化为高价值和能量密集型产物。然而,氧化态铜物种在反应条件下的性质和稳定性在文献中存在诸多争议。在此,我们展示了具有离散Cu-O配位环境的钛酸铜纳米催化剂的合成与表征,用于电化学CO₂还原反应(CORR)。我们采用实时原位X射线吸收光谱(XAS)来监测中性pH值CORR条件下的铜物种。伏安法和在线电化学质谱与XAS结果相结合表明,钛酸根基序促进了氧化态铜物种在还原条件下长时间的保留,而其本身不具备任何CORR活性。此外,我们证明了Cu-O环境的具体性质和催化剂的尺寸决定了氧化态铜物种的长期稳定性,进而决定了产物选择性。