Synthesis of Composition-Tunable Syngas from Efficiently Electrochemical Conversion of CO₂ over AuCu/CNT Bimetallic Catalyst

Abstract

Syngas is significant for the chemical industry for the synthesis of a variety of hydrocarbon fuels and chemicals. Different syngas-based products require syngas with different CO/H 2 ratios, which depend mainly on the design of the catalyst. Under this background, we successfully synthesized syngas by electroreduction of carbon dioxide (CO 2 ) with a controllable CO/H 2 ratio over a AuCu bimetallic catalyst. In contrast to the monometallic Au and Cu catalysts, the AuCu bimetallic catalyst gives a 95.2% of Faradaic efficiency (FE) at only 290 mV on the selective conversion from CO 2 to CO. By tuning the Cu/Au ratio and potential during the electrochemical conversion, the H 2 /CO in the obtained syngas products can be obtained at the wide range of 0.12 to 5.24. We propose that the controllable H 2 /CO ratio from CO 2 is significant in industrial production and will decrease the cost of catalyst fabrication.

Renewable Power for Electrocatalytic Generation of Syngas: Tuning the Syngas Ratio by Manipulating the Active Sites and System Design

“…% leading to a higher syngas ratio (i. e., the active site for HER). [151] More specifically, a syngas ratio of 0.75 was attained at À 0.9 V with AuCu 8 /CNT at a high j of À 20 mA cm À 2 . Many industrially applicable syngas ratios were produced by varying the applied potential and Cu wt.…”

“…[52,59] In the search for more cost-effective and active metal-based catalysts, Cu has been incorporated with both Au and Zn NPs in carbon nanotubes, with syngas ratios able to be tuned through the manipulation of the composition and loading of metals. [149,150] With Au/Cu CNTs (deposited on the CNTs through an aqueous reduction method), syngas ratios of 0.1 to 5.2 have been achieved, with an increase in the Cu wt. % leading to a higher syngas ratio (i. e., the active site for HER).…”

Selectively Converting Carbon Dioxide to Syngas over Intermetallic AuCu Catalysts

“…21−25 Nevertheless, the low faradic efficiency (FE) and poor activity endow the limited application of precious monometallic Au nanocatalysts. 26 In this regard, alloying Au with the second element (e.g., Cu) is reported to efficiently control the hydrogen evolution and then tune the selectivity of CO 2 reduction. 27−32 For instance, Cuenriched Au electrodes prepared by the electrochemical underpotential deposition demonstrate the sensitive production of CO and H 2 , as the Cu enrichment systematically alters the binding affinity of CO* intermediates.…”

“…Among various metal catalysts, Au is regarded as the typical catalyst for the reduction of CO 2 and the production of syngas. , Subsequently, various strategies have been developed to prepare different Au nanocatalysts for the controllable generation of syngas. − Nevertheless, the low faradic efficiency (FE) and poor activity endow the limited application of precious monometallic Au nanocatalysts . In this regard, alloying Au with the second element (e.g., Cu) is reported to efficiently control the hydrogen evolution and then tune the selectivity of CO 2 reduction. − For instance, Cu-enriched Au electrodes prepared by the electrochemical underpotential deposition demonstrate the sensitive production of CO and H 2 , as the Cu enrichment systematically alters the binding affinity of CO* intermediates .…”

Synthesis of Bimetallic Au-Ag/CMK-3 Catalysts and Their Catalytic Activity for the Oxidation of Amino Alcohol

“…Au catalysts have attracted extensive attention because of their superior catalytic performance in many important reactions, such as CO oxidation, , oxidation of alcohols, − hydrogenation of unsaturated C–C bonds, , reduction of nitrocompounds, and synthesis of H 2 O 2 . , To modify and improve their intrinsic catalytic properties, bimetallic nanoparticles containing Au, including Au-Pd, − Au-Pt, − Au-Ag, , Au-Ni, and Au-Cu, , were intensively constructed, which has been proven to be an efficient way to tune the electronic and geometric features of Au-based catalysts with improved catalytic performance in a variety of reactions. ,, Among these bimetallic nanoparticles, the Au-Ag alloy is one of the most attractive catalyst with ultrahigh catalytic performance.…”