Fig. 7: Impact of surface morphology on CO2RR selectivity for well-defined UHV-prepared Cu(111) and Cu(100) single crystals.
From: Structure Sensitivity and Catalyst Restructuring for CO2 Electro-reduction on Copper
LT-STM images on UHV-prepared (a, b) pristine Cu(111); c, d Cu(111) surface after five successive cycles of CO2RR followed by sputtering and subsequent annealing in UHV (noted as stepped Cu(111)); e, f pristine Cu(100); g, h intermediate Cu(100) and (i, j) stepped Cu(100), which are Cu(100) surface after one and two CO2RR cycles, followed by sputtering and subsequent annealing in UHV, respectively. The distribution of the step edge length in dependence on the step edge angle of the respective surfaces is shown in (k–o). For Cu(100), the insets show an atomic model of the most prominent step-edge direction. The Faradaic Efficiencies (FE), which are obtained after 1 h of CO2RR at − 1.1 V vs. RHE in 0.1 M KHCO3, as well as the calculated step edge density for the respective surfaces, are displayed in (p–t). The LT-STM image in (d) and FE data are partially adapted from Nguyen et. al with permission10. For electrochemical measurements, the error bars stem from averaging the product selectivities over 1 hr. For step density, the error bar stems from the standard variation of the measured step edges.
