Patent ID: 8323611

Claim:
A solid acid catalyst represented by HTi x Nb y O 5 , wherein x is 1.1<x<1.2 and y is 0.9>y>0.8, having a Ti/Nb atomic ratio z of 1.2<z<1.4, obtained by proton changing of alkali metal cation of cation changeable lamellar metal oxide in which polyanion nano-sheet comprising lamellar metal oxide layers of titanium niobate lying alkali metal cation between are regularly laminated by inorganic acid or organic acid adjusted to 0.0001M to 1M, delaminating said laminated layers temporarily by inserting cation selected from the group consisting of organic amine or organic ammonium between layers of proton exchangers, preparing an aqueous colloidal solution comprising metal oxide sheets to which said organic amine or organic ammonium is absorbed, then proton exchanging said organic amine or organic ammonium by adding inorganic acid or organic acid adjusted to 0.0001M to 1M to said aqueous colloidal solution and simultaneously coagulating on titanium niobate nano-sheet.