Ultrastable Cu Catalyst for CO₂ Electroreduction to Multicarbon Liquid Fuels by Tuning C–C Coupling with CuTi Subsurface

Abstract

Production of multicarbon (C2+) liquid fuels is a challenging task for electrocatalytic CO2 reduction, mainly limited by the stabilization of reaction intermediates and their subsequent C−C couplings. In this work, we report a unique catalyst, the coordinatively unsaturated Cu sites on amorphous CuTi alloy (a‐CuTi@Cu) toward electrocatalytic CO2 reduction to multicarbon (C2‐4) liquid fuels. Remarkably, the electrocatalyst yields ethanol, acetone, and n‐butanol as major products with a total C2‐4 faradaic efficiency of about 49 % at −0.8 V vs. reversible hydrogen electrode (RHE), which can be maintained for at least 3 months. Theoretical simulations and in situ characterization reveals that subsurface Ti atoms can increase the electron density of surface Cu sites and enhance the adsorption of *CO intermediate, which in turn reduces the energy barriers required for *CO dimerization and trimerization.

Boosting CO2 electroreduction towards C2+ products via CO* intermediate manipulation on copper-based catalysts

“…This method by constructing a metal-substrate interface to increase the oxidation state of Cu provides an avenue to promote C-C coupling. Extensive experimental results have shown that Cu + on non-copper substrates such as metal oxides, 118,119 nitrides 120 and even metals 121 can also promote the formation of C 2+ products. For example, Lee et al synthesized Cu/ceria catalysts (sub-10 nm) with a high density of interfaces and interconnected structure of CuO and CeO 2 nanocrystals by impregnating a copper precursor into ceria/C and subsequent calcination in air (Fig.…”

Selective CO2 Photoreduction to Acetate at Asymmetric Ternary Bridging Sites

“…The band at around 887 cm −1 is designated to C− C−O stretching for acetic acid formation. 37,38 This band is an indicator for the C−C coupling to produce C 2 products during CO 2 reduction. The band at around 1034 cm −1 is related to C−O−H stretching and/or CH 3 rocking.…”

“…Moreover, the band at around 2909 cm −1 is assigned to C�O stretching vibration for CO*, validating the CO* coupling to generate acetic acid. 38,39 To further unveil CO 2 reduction intermediates, in situ FTIR measurements are conducted for CO 2 reduction on r-In 2 O 3 / InP (Figure 6g). Under visible light irradiation, a set of peaks appears which are strengthened over irradiation time.…”

Rational Manipulation of Intermediates on Copper for CO2 Electroreduction Toward Multicarbon Products

“…Moreover, Cu supported on amorphous CuTi alloys (a-CuTi@Cu) can electroreduce CO 2 to C 2−4 products, such as ethanol, propanol, and n-butanol (Fig. 8b) [121]. Theoretical simulations and in situ characterization demonstrate that the subsurface Ti atoms increase the electron density of the surficial Cu sites with improved adsorption ability of *CO intermediates.…”