. 2022 Jan 4;12(2):1037–1051. doi: 10.1021/acscatal.1c04978

Table 1. Summary of Ion Transport Processes, the Conditions Emerging at the Membrane Surface, and the Main Obstacles during CO₂ Electrolysis Using Different Ion Exchange Membranes.

	surface pH		surface species
	anode	cathode	anode	cathode	transporting ions	main obstacle(s)
CEM	acidic	acidic	H⁺, anolyte	H⁺, CO₂, cations	H⁺, cations from anolyte	predominant cathodic HER
AEM	∼neutral	alkaline	CO₃^2–	OH^–, CO₂, HCO₃^–, CO₃^2–	OH^–, HCO₃^–, CO₃^2–, (cations from anolyte)	CO₂ crossover
r-BPM	alkaline	acidic	OH^–, anolyte	H⁺, CO₂	H⁺ and OH^–	Predominant cathodic HER
f-BPM	acidic	alkaline	H⁺, anolyte	OH^–, CO₂, HCO₃^–, CO₃^2–	OH^–, HCO₃^–, CO₃^2– and H⁺, cations from anolyte	CO₂ formation between the membranes

Table 1. Summary of Ion Transport Processes, the Conditions Emerging at the Membrane Surface, and the Main Obstacles during CO2 Electrolysis Using Different Ion Exchange Membranes.