Increasing risks from global warming impose an urgent need to develop technologically and economically feasible means to reduce CO2 content in the atmosphere. Carbon capture and utilization technologies and carbon markets have been established for this purpose. Electrocatalytic CO2 reduction reaction (CO2RR) presents a promising solution, fulfilling carbon-neutral goals and sustainable materials production. This review aims to elaborate on various components in CO2RR reactors and relevant industrial processing. First, major performance metrics are discussed, with requirements obtained from a techno-economic analysis. Detailed discussions then emphasize on (i) technical benefits and challenges regarding different reactor types, (ii) critical features in flow cell systems that enhance CO2 diffusion compared to conventional H-cells, (iii) electrolyte and its effect on liquid phase electrolyzers, (iv) catalysts for feasible products (carbon monoxide, formic acid and multi-carbons) and (v) strategies on flow channel and anode design as next steps. Finally, specific perspectives on CO2 feeds for the reactor and downstream purification techniques are annotated as part of the CO2RR industrial processing. Overall, we focus on the component and system aspects for the design of a CO2RR reactor, while pointing out challenges and opportunities to realize the ultimate goal of viable carbon capture and utilization technology.

2,5-Furandicarboxylic acid (FDCA) is a platform chemical for polyethylene furanoate (PEF) manufacturing, a promising biobased and green alternative to polyethylene terephthalate (PET) with a market size of 1.8 million tonne/ annum. There are several routes to produce FDCA, all through 5hydroxymethylfurfural (HMF) conversion. The traditional thermochemical process is highly energy intensive with a low yield. The electrocatalytic pathway, on the other hand, is gaining increased interest for it makes the process control more efficient, achieves a higher yield, and more importantly can be driven by renewable electricity to lower the environmental impact compared to the thermochemical process. This study assesses the economic aspects and environmental impacts of the electrochemical production of FDCA. It is found that the net present value (NPV) of the integrated electrochemical conversion and product separation plant is highly profitable, $72 million for 100 tonne/day production of FDCA, under optimistic conditions. It also reveals that the HMF price has significant impact on process economics, and the current density has the largest scope of improvement. The life-cycle assessment (LCA) results indicate that processes related to HMF production contribute the most to the overall environmental impactscalling for low impact HMF production processes, with cost reductionshowever, the impacts of the electrochemical route are much lower in comparison with the thermochemical route.

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Recent advancement on carbon dioxide reduction reaction (CO2RR) has shown promising results on CO2 conversion to value-added carbon products as renewable fuels or valuable chemical feedstocks. Formic acid is one of the products that requires low applied voltage in CO2RR. However, it remains with a low full cell energy efficiency, mainly due to the large full cell applied potential. Traditionally, the anodic reaction is carried out with oxygen evolution reaction (OER), which requires a higher applied potential on the counter electrode. This work reports a viable alternative anodic reaction on electro-oxidative upgrading of biomass-derived 5-hydroxymethylfurfural (HMF) into valorized chemicals such as furandicarboxylic acid (FDCA) using Ni-based catalyst. Experimental results have demonstrated that in the combined electrolyzer, the Faradaic efficiency of formate can increase from 41% to 76%, while keeping the applied potential as low as 2 V for achieving a current density of 10 mA/cm2. In addition, at the anode, the Faradaic efficiency reached 60% towards FDCA using the same combined setup. It is postulated that due to the lower overpotential at anode, the cathodic potential becomes more negative for the same current density, and hence a higher Faradaic efficiency towards formate can be attained. Moreover, compared to conventional systems with OER, the combined system is able to produce a value-added product such as FDCA with a considerable FE, approaching a more economic application.