Copper/alkaline earth metal oxide interfaces for electrochemical CO2-to-alcohol conversion by selective hydrogenation

Hydrophobic, Ultrastable Cuδ+ for Robust CO2 Electroreduction to C2 Products at Ampere-Current Levels

“…These results demonstrate that the local H proton consumption in the electrolyte around the Cu CF catalyst was steadier than that for the Cu Ref catalyst, maintaining a stable local microenvironment and keeping the durability of C 2+ products. Furthermore, we observed that the signals arise from the CO stretching of the adsorbed CO on the catalyst in the range of 1800–2150 cm –1 . , As reported, the regions below and above 2000 cm –1 were attributed to the bridge-bound CO (CO bridge ) and atop-bound CO (CO atop ) configurations, respectively, suggesting that the *CO intermediates were mainly bounded in the atop and bridge sites on the Cu CF catalyst (Figure e) . However, the CO stretching band on the Cu Ref catalyst was only from CO atop (Figure S42).…”

“…15 Furthermore, the CO atop stretching bands were deconvoluted into two bands, in which the low-frequency C�O stretching band was assigned to a dynamic *CO intermediate that contributed to the ensuing C−C coupling as reported in previous studies. 10 We calculated the relative intensities of CO atop and CO bridge of Cu CF at various applied potentials, showing that the CO atop and CO bridge ratio on the Cu CF catalyst kept a steady trend (Figure 3f). We further analyzed the relative intensities of the low-frequency and high-frequency bands (Ratio low/high ), showing that the Cu CF catalyst showed a higher Ratio low/high value than that of the Cu Ref catalyst (Figures 3g, S43 and S44).…”

“…Electroreduction of carbon dioxide (CO 2 RR) to value-added products using renewable energy offers a feasible pathway to realize carbon-neutral energy cycle. , Among various CO 2 RR products, multicarbon (C 2+ ) products, such as C 2 H 4 , C 2 H 5 OH, and CH 3 COOH, have attracted wide attention due to their high energy densities. − Efficient CO 2 -to-C 2+ convention involves multiple proton-coupled electron transfer processes, which accompanied with multiple intermediates on catalytic sites often lead to a low activity and selectivity. Therefore, it is important and challenging to develop effective electrocatalysts for CO 2 RR. , Copper (Cu) materials showed great promise to promote selective electroreduction of CO 2 to C 2+ products with a high conversion efficiency. − Recent studies have demonstrated that the moderate oxidation state of Cu (Cu δ+ ) played a critical role in steering the CO 2 RR pathway toward the high-efficacy C 2+ formation. − However, Cu δ+ active sites are extremely unstable during CO 2 RR, and various strategies, including plasma treatment, heteroatom doping, and organic molecular modification, have been explored to stabilize Cu δ+ . ,,− Recent advances have improved the Faradaic efficiency (FE) toward C 2+ products up to around 80 to 90%. ,− In spite of these efforts, Cu δ+ sites still suffer from the in situ self-reduction during CO 2 RR. This makes it very difficult to maintain a high CO 2 RR activity, especially at high operating current densities …”

Defect engineering of two-dimensional materials for advanced energy conversion and storage

“…[309][310][311][312] Generally, the CO 2 RR mainly contains three steps: the chemical adsorption of CO 2 on active sites, the electron and/or proton transfer to break C-O bonds and/or form C-H bonds, and the desorption of reduction products. [313][314][315] Among these processes, the second step is a proton-coupled multi-step reaction potentially containing varied electron transfer pathways. Affected by the binding state of intermediates, various reduction products can be synthesized, such as CO, HCOOH, CH 4 , HCHO, CH 3 OH, C 2 H 4 , C 2 H 5 OH, and n-C 3 H 7 OH.…”

Killing Two Birds with One Stone: Upgrading Organic Compounds via Electrooxidation in Electricity-Input Mode and Electricity-Output Mode

“…Therefore, it is imperative to develop clean and renewable alternatives for energy storage and chemical conversion. With the remarkable renaissance of electrochemical technology, and the constant inventions in the rapid development of renewable-based electricity technology, the technology of energy storage and conversion into chemicals is attracting great interest [ 1 , 2 , 3 , 4 , 5 , 6 ]. For example, hydrogen, a clean, flexible, cost-effective energy carrier for net-zero carbon (carbon-free) strategies, features a higher enthalpy of combustion (H 2 (g) + ½O 2 (g) → H 2 O(l) ΔH = −285.8 kJ/mol, high specific-energy-density) and enables the possibility of attaining secure and clean energy in the future.…”