The decomposition of methanol over copper particles incorporated in the interlayer regions of zinc aluminum silicate hydroxide, reduced CuO/Zn-mica and Cu2+/Zn-mica, was studied. CuO/Zn-mica reduced with H, is high active for the decomposition, compared with reduced Cu2+/Zn-mica. Methanol is selectively converted at 200 degreesC to H-2 and CO in reduced CuO/Zn-mica, whereas the methanol decomposition over reduced Cu2+/Zn-mica forms formaldehyde as a by-product. IR data support that the decomposition over reduced CuO/Zn-mica proceeds via copper methoxide and/or copper formate as an intermediate. An adsorption of NH3 shows that the amount of the adsorption on reduced CuO/Zn-mica is about six times as large as that on reduced Cu2+/Zn-mica. The results indicate the difficulty of the reduction of copper ion in Cu2+/Zn-mica, compared with CuO/Zn-mica. These results support that the active site for methanol decomposition on reduced CuO/Zn-mica is metallic Cu in the interlayer regions of Zn-mica. (C) 2002 Elsevier Science B.V. All rights reserved.