Highly Selective and Active Pd‐In/three‐dimensional Graphene with Special Structure for Electroreduction CO₂ to Formate

Abstract

Electrocatalytic reduction of CO 2 to formate on carbon based electrodes is known to suffer from low electrochemical reaction activity and product selectivity. Pd/three-dimensional graphene (Pd/3D-RGO), In/3D-RGO and Pd-In/3D-RGO for the electrochemical reduction of CO 2 were prepared by a mild method that combines chemical and hydrothermal. The metal/3D-graphenes (metal/3D-RGO) were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry and the ion chromatography were performed to investigate the electrochemical performance of the metal/3D-RGO. The morphology and dispersion of metal/3D-RGO are 3D structure with amount of interconnected pores with metal NPs loading on the fold. And the Pd 0.5 -In 0.5 /3D-RGO show excellent surface performance with well dispersion and smallest particle size (12.8 nm). XPS reveal that binding energy of Pd (In) NPs is shifted to negative energy, for the metal lose electrons in metal and combine with C, which is demonstrated in the HNO 3 experiment. The peak potential of Pd 0.5 -In 0.5 /3D-RGO is À0.70 V (vs. Ag/AgCl), which is more positive than In 1.0 /3D-RGO (À0.73 V) and Pd 1.0 / 3D-RGO (À1.2 V). The highest faradaic efficiency (85.3 %) happens in Pd 0.5 -In 0.5 /3D-RGO at À1.6 V vs. Ag/ AgCl. In these experiments, the special structure that metal NPs combine with C and the bimetal NPs give a direction to convert CO 2 to formate.

Recent Advances in Electrochemical CO2 Reduction on Indium‐Based Catalysts

“…As compared to Pd/3D-RGO or In/3D-RGO, the Pd 0.5 -In 0.5 /3D-RGO catalyst showed the highest Faradaic efficiency for formate (85.3 %) and was stable for 24 h at À 1.6 V vs. Ag/AgCl in 0.5 M KHCO 3 electrolyte. [113] The improved catalytic performance was considered to be related to the small particle size (12.80 � 0.05 nm) and high particle dispersion.…”

Three‐Dimensional Graphene‐Based Structures: Production Methods, Properties, and Applications

“…For instance, an electrically conductive and porous 3D graphene network has been prepared via mild chemical reduction of GO by sodium bisulfide at 95°C under atmospheric pressure and in the presence of iron oxide nanoparticles [43]. He et al [44] reported the facile fabrication of 3D graphene sponges containing palladium and indium by combination of the hydrothermal and chemical reduction techniques. In this study, GO aqueous solution containing palladium and indium salts and vitamin C as reducing agent were treated hydrothermally at 110°C for 6 h.…”

Three-Dimensional Cathodes for Electrochemical Reduction of CO2: From Macro- to Nano-Engineering

“…The Pd/three-dimensional graphene-based catalyst (Pd/3D-rGO), In/3D-rGO and Pd-In/3D-rGO) for CO 2 RR to formate were prepared by chemical and hydrothermal methods. The most optimal nanocatalyst, Pd 0.5 -In 0.5 /3D-rGO, with a particle size of 12.8 nm, demonstrates a high Faradaic efficiency of 85.3% at 1.6 V (Ag/AgCl) and a peak potential of 0.70 V (Ag/AgCl), which is more positive than In1.0/3D-RGO (−0.73 V) and Pd1.0/3D-RGO (−1.2 V) [106].…”

“…This work reviewed recent progress in three-dimensional (3D) cathodes for CO 2 reduction. In the literature, these cathodes have been either purposely constructed to be three-dimensional, or have had the potential to serve as three-dimensional [104][105][106][107][108]. 3D cathodes with hierarchically porous nanostructures offer many benefits, and are one of the most effective strategies to resolve the abovementioned challenges [109][110][111][112][113][114][115][116].…”