C 1s peak fitting XPS data for reduced cat-400 before and after the lifetime test of 200 h.

Sample	Carbonous type	Binding energy (eV)	n c (%)
Fresh	C 1s C–O	288.4	65.2
	C 1s C–C	284.8	23.9
	C 1s C O	292.6	10.9
Spent	C 1s C–O	286.8	12.7
	C 1s C–C	284.8	76.3
	C 1s C O	289.2	11.0