Maaike E T Vink-van Ittersum, Erik Betz-Güttner, Eric Hellebrand, Claudia J Keijzer, Matt L J Peerlings, Peter Ngene, Petra E de Jongh
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引用次数: 0
Abstract
The electrochemical reduction of CO2 combined with efficient CO2 capture is a promising approach to close the carbon cycle. We studied the effect of pore size on the activity and selectivity of porous Ag electrodes using template-based electrodes as model catalysts. Using polymer spheres with sizes between 115 nm and 372 nm as templates, ordered porous Ag catalysts with different pore diameters were obtained. These well-defined model systems allowed us to understand the effect of pore size on CO and H2 production. At the most cathodic potential, around -1.05 V, up to 4 times more CO than H2 was formed. The intrinsic CO production depends on the pore size, as it increases when changing the pore diameters from ∼100 nm to ∼300 nm. At pore diameters above ∼300 nm, the pore size does not affect the intrinsic CO production anymore. For the first time, FIB-SEM was used to quantitatively analyse the porosity of the electrodes and correlate it with trends in intrinsic activity. The catalyst with a pore diameter of ∼200 nm had the highest tortuosity of 2.41, which led to an increased CO production. The catalysts with a pore diameter of ∼200 nm and smaller have pore networks that are twice as long as the pore network of catalysts with ∼400 nm pores. This leads to an additional potential drop, which lowers the effective driving force for the electrochemical reaction. Disentanglement of these different factors is important for rational design of porous CO2 reduction catalysts.
期刊介绍:
Reaction Chemistry & Engineering is a new journal reporting cutting edge research into all aspects of making molecules for the benefit of fundamental research, applied processes and wider society.
From fundamental, molecular-level chemistry to large scale chemical production, Reaction Chemistry & Engineering brings together communities of chemists and chemical engineers working to ensure the crucial role of reaction chemistry in today’s world.