Nanoporous PdCo Catalyst for Microfuel Cells: Electrodeposition and Dealloying

Table 1

Oxygen reduction reaction characteristics of the PdCo catalysts evaluated in 0.5 M H₂SO₄ compared with those of Pt electrode and Pd electrode.

		Electrode performance^b/mA cm^−2		Specific activity^e/μA cm^−2
	Onset potential^a/V	0.65 V versus Ag/AgCl	0.60 V versus Ag/AgCl	0.65 V versus Ag/AgCl	0.60 V versus Ag/AgCl	Tafel slope/mV decade^−1	Roughness factor/−	Ref.
Pt electrode^f	0.72	3.5 × 10^−2	1.1 × 10^−1	8.4	2.7 × 10^1	71^c, 116^d	4.2	[60]
Pd thin film^g	0.58	1.0 × 10^−4 h	5.8 × 10^−4 h	3.4 × 10^−2 h	1.9 × 10^−1 h	67	3.1	[11]
PdCo thin film^f	0.66	2.4 × 10^−2	2.6 × 10^−1	1.5	1.6 × 10^1	44	16	[60]
PdCo dendrite^g	0.68	5.7 × 10^−2	6.2 × 10^−1 h	4.4	4.7 × 10^1 h	48	13	[15]
Modified PdCo dendrite^g	0.71	1.9 × 10^−1	1.6^h	1.1 × 10^1	9.2 × 10^1 h	55	17	[15]
Nanoporous PdCo thin film^f	0.69	3.5 × 10^−1	2.5	8.6	6.2 × 10^1	43	41	[60]
Nanoporous PdCo dendrite^g	0.72	3.9 × 10^−1 i	—	1.3^i	—	—	290	[29]

^aat the current density of 1 μA cm⁻² (electrochemically active surface area). ^bbased on the geometrical surface area. ^c0.7–0.75 V. ^d0.55–0.65 V. ^ebased on the electrochemically active surface area. ^fmeasured by hydrodynamic voltammetry at room temperature (22°C). ^gmeasured by linear sweep voltammetry at (30°C). ^hestimated by extrapolating the Tafel slope. ⁱwith a slight mass-transfer limitation.