Boosted C–C coupling with Cu–Ag alloy sub-nanoclusters for CO ₂ -to-C ₂ H ₄ photosynthesis

Abstract

The selective photocatalytic conversion of CO 2 and H 2 O to high value-added C 2 H 4 remains a great challenge, mainly attributed to the difficulties in C–C coupling of reaction intermediates and desorption of C 2 H 4 * intermediates from the catalyst surface. These two key issues can be simultaneously overcome by alloying Ag with Cu which gives enhanced activity to both reactions. Herein, we developed a facile stepwise photodeposition strategy to load Cu–Ag alloy sub-nanoclusters (ASNCs) on TiO 2 for CO 2 photoreduction to produce C 2 H 4 . The optimized catalyst exhibits a record-high C 2 H 4 formation rate (1110.6 ± 82.5 μmol g −1 h −1 ) with selectivity of 49.1 ± 1.9%, which is an order-of-magnitude enhancement relative to current work for C 2 H 4 photosynthesis. The in situ FT-IR spectra combined with DFT calculations reveal the synergistic effect of Cu and Ag in Cu–Ag ASNCs, which enable an excellent C–C coupling capability like Ag and promoted C 2 H 4 * desorption property like Cu, thus advancing the selective and efficient production of C 2 H 4 . The present work provides a deeper understanding on cluster chemistry and C–C coupling mechanism for CO 2 reduction on ASNCs and develops a feasible strategy for photoreduction CO 2 to C 2 fuels or industrial feedstocks.

Overcoming Electrostatic Interaction via Pulsed Electroreduction for Boosting the Electrocatalytic Urea Synthesis

“…However, further Cu LMM AES spectra show that the binding energies (BEs) of Cu 2+ for CuGeO 3 , and CuSnO 3 shift negatively to 571.4 eV and 569.7 eV, respectively (Figure S5). This result indicates the Si can promote the electron transfer from Cu to O than Ge and Sn, enhancing the stability of Cu 2+ , resulting a reconstruction‐resistant atomic Cu−O−Si Interface of CuSiO x [19] . The results of Brunauer–Emmett–Teller (BET) reveal that the specific surface area of CuSiO x is an impressive 461.9 m 2 /g (Figure S14), which is much higher than that of the CuGeO 3 (Figure S15, 9.9 m 2 /g) and CuSnO 3 (Figure S16, 25.3 m 2 /g).…”

Overcoming Electrostatic Interaction via Pulsed Electroreduction for Boosting the Electrocatalytic Urea Synthesis

“…This result indicates the Si can promote the electron transfer from Cu to O than Ge and Sn, enhancing the stability of Cu 2 + , resulting a reconstructionresistant atomic CuÀ OÀ Si Interface of CuSiO x . [19] The results of Brunauer-Emmett-Teller (BET) reveal that the specific surface area of CuSiO x is an impressive 461.9 m 2 /g (Figure S14), which is much higher than that of the CuGeO 3 (Figure S15, 9.9 m 2 /g) and CuSnO 3 (Figure S16, 25.3 m 2 /g).…”

Enhancing CO2 Electroreduction Performance through Si-Doped CuO: Stabilization of Cu+/Cu0 Sites and Improved C2 Product Selectivity

“…The circuit was then connected, and spectra were collected at different potentials (Figures 4d and S24). The adsorption of CO 2 and H 2 O on the surface of CuO-Si induces the formation of H 2 O* (1640 cm −1 ), 60,61 (HCO 3 − , 1420 cm −1 ), 61,62 with high peak intensities, indicating a strong adsorption of CO 2 . With increasing the test voltage, the spectral intensity for *COOH (1180 and 1560 cm −1 ) progressively amplifies, spotlighting *COOH as a pivotal intermediate in steering CO 2 RR to C 2 products.…”