Performances and results of CO₂R to formic acid/formate (HCOOH/HCOO⁻) by CO₂ reactors with different designs.

Reactor design	Electrocatalysts	Electrolyte	Potential (V vs. RHE)	Current density (mA cm−2)	FE (%)	Ref.
H-cell	Electrodeposited Bi dendrites	0.5 M KHCO3	−1.0	38.1	92	61
	Sn/SnOx	0.1 M KHCO3	−1.2	11.2	89.6	62
	Sulfur-doped indium	0.5 M KHCO3	−0.98	∼60	93	63
	PdPt/C	0.1 M K2HPO4/0.1 M KH2PO4	−0.4	5	88	64
	Bi–PMo nanosheets	0.5 M NaHCO3	−0.86	30	93	65
Flow cell	In/Pb	1 M NaHCO3		40	80	66
	Chain-like mesoporous SnO2	0.1 M KHCO3	−1.06	13.6	95	67
	Sn nanoparticles (commercial)	1 M KOH anolyte	−0.2	51.7	93.3	31
	Sn/C-GDE	DI water	3.3	140	94	50
	2D-Bi GDE	0.25 M K2SO4	3	30	80	34
GDE	SnOx–CNT	0.5 M KHCO3	−1.25	10	77	68
	Ru, Pd alloy particles	0.5 M KHCO3	−1.1 V vs. NHE	80	90	69
	CuSn alloy particles	1 M KOH	−1.0	148	82	70
	Sn particles/C-GDE	0.45 mol L−1 KHCO3 + 0.5 mol L−1 KCl	−1.3	90	70	71
	SnO2/C-GDE	0.1 M KHCO3	2.5	133	81	72
MEA	Commercial Sn with a GDE	0.5 M KHCO3	−1.3	150	60	73
	Sn powder	0.1 M KHCO3	−1.7	9	90	52
	Sn nanostructure	—	−0.7	5	12.5	37
	SnO2 catalyst carbon black	1.0 M KOH	−1.43	251	80	74
MR	RuPd/Sn	0.5 M KCl + 1 M HCl	−0.55	100	89	56
	Sn nanocatalyst/graphite rod	0.5 M KHCO3	2.5	—	84.25	75
	SnO2 nanoparticles	1 M KOH	0.95	147	97	76