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Metal alloy electrocatalysts are commonly used in electrochemical (EC) CO 2 reduction. In this study, we demonstrate the application of a ternary CuNiZn alloy as an electrocatalyst for both CO 2 and CO reductions. Our results show that formate, CO, CH 4 , and C 2−7 hydrocarbons were produced through the process of initial CO 2 adsorption followed by subsequent stepwise reactions. Interestingly, we also observed the production of CH 4 and C 2−7 hydrocarbons (C n H 2n+2 and C n H 2n ) through EC CO reduction, which occurred via direct CO adsorption, followed by hydrogenation reactions. Furthermore, we discovered an electrochemically-induced surface reaction that mimics the Fischer−Tropsch (F−T) synthesis, resulting in the formation of long-chain hydrocarbons through C−C coupling/polymerization. We utilized X-ray photoelectron spectroscopy with Ar + ion sputtering depth to investigate the interfacial electronic structures and surface elemental composition distributions of Cu, Ni, and Zn. Our results indicate that these properties are highly dependent on both the applied potential and the depth at which they are measured. These unique observation provides significant insights into the EC F−T synthesis process, C−C coupling mechanism, the design of efficient metal alloy electrodes, and the theoretical modeling of alloys in both electrochemical CO 2 reduction and CO reduction.

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The trivalent Eu(III) ion exhibits unique red luminescence and plays an significant role in the display industry. Herein, the amperometry electrodeposition method was employed to electrodeposit Eu(III) materials on porous Si and terpyridine-functionalized Si surfaces. The electrodeposited materials were fully characterized by scanning electron microscopy, X-ray diffraction crystallography, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. Photoluminescence (PL) spectroscopy revealed that PL signals were substantially increased upon deposition on porous Si surfaces. PL signals were mainly due to direct excitation and charge-transfer-indirect excitations before and after thermal annealing, respectively. The as-electrodeposited materials were of a Eu(III) complex consisting of OH, H2O, NO3−, and CO32− groups. The complex was transformed to Eu2O3 upon thermal annealing at 700 °C. The electrodeposition on porous surfaces provide invaluable information on the fabrication of thin films for displays, as well as photoelectrodes for catalyst applications.