Patent ID: 7935653

Claim:
A metal oxide nanoporous material which comprises two or more kinds of first metal oxides selected from the group consisting of alumina, zirconia, titania, iron oxide, rare-earth oxides, alkali metal oxides and alkaline-earth metal oxides, the metal oxide nanoporous material having nanopores, each with a diameter of 10 nm or smaller, and the metal oxides being dispersed homogeneously in a wall forming the nanopores, wherein, when a spectrum of a tested sample of the nanoporous material is measured at measurement points located in regions where the tested sample has an approximately equal thickness by energy dispersive X-ray spectroscopy using a transmission electron microscope with a 200 kV accelerating voltage and a 1.0 nm diameter of electron beam, and when a relative intensity ratio X, a mean value X m and a second moment ν 2 around the mean value X m are calculated for every one of metal elements of the metal oxides contained in the nanoporous material in an amount not lower than 10 at %, the relative intensity ratio being calculated by converting an integrated intensity of the peaks of X-ray fluorescence for each metal element in measured spectra into a relative ratio, the calculated X m and ν 2 for every one of the metal elements of the metal oxides contained in the nanoporous material in not lower than 10 at %, will satisfy a condition expressed in the following formula (1): ν 2 /X m 2 ≦0.02 (1) wherein, in the formula (1), X m is a mean value of the relative intensity ratios X, expressed as X m =(ΣX)/N (N being a number of the measurement points); ν 2 is the second moment around the mean value X m ,expressed as ν 2 ={Σ(X−X m ) 2 }/N; and ν 2 /X m 2 is the second moment normalized by the mean value X m squared.