Table 2.

Variation of sensor components.

Pt content of the zeolite layer	Reduction route of the zeolite	Number of zeolite layers/thickness of zeolite layer	Thickness of the Cr2O3 layer d
1 wt%	NaBH4	1/25 μm	251 nm
2 wt%	H2	2/50 μm	150 nm
3 wt%		3/75 μm	75 nm
		4/100 μm