Table 2. XPS Elemental Ratios and Oxidation State Ratios before and after Catalytic Stability Tests with N_0.25Rh_1.75P/C and Rh₂P/C.

	Ni0.25Rh1.75P (ideal Rh/Ni/P = 58:9:33)				Rh2P (ideal Rh/P 67:33)
	Rh/Ni/P	Rh	Ni	P	Rh/P	Rh	P
		(Rh–P):Rh3+	(Ni–P):Ni2+/Ni3+	(P-M):PO43–		(Rh–P):Rh3+	(P-M):PO43–
before	31:59:10	63:37	18:38:44	16:84	92:8	80:20	48:52
after HER	25:72:3	59:41	17:30:53	19:81	95:5	75:25	56:44
after OER	30:68:2	65:35	9:45:46	27:73	94:6	62:38	42:58