Abstract: A novel solution route has been developed that after heat-treatment to 500-600° C. under inert atmosphere, yields highly porous composites of nano-sized metal (Ni) particle inclusions in ceramics (Al2O3). Metal loadings could be made from <1% to >95% Ni. The metal inclusion sizes in the Ni—Al2O3 system with the 10 atom % Ni sample were 4-7 nm, while for the 75 atom % Ni sample they were 5-8 nm. It was shown that the 10 atom % Ni sample could be used as a catalyst for the conversion of CO2 and CH4 in the temperature range 550-700° C., while higher temperatures led to growth of the Ni particles and carbon poisoning over time. The solution routes could also be deposited as thin dense films containing <10 nm Ni particles. Such films with high Ni-particle loadings deposited on aluminium substrates have shown very good solar heat absorber proficiency and provide good substrates for carbon tube growth.

Abstract: A method of making a hard constituent powder coated with at least one iron group metal, Me, by dissolving and complex binding at least one of Me.sub.n (NO.sub.3).sub.m and Me.sub.n (SO.sub.4).sub.m and other similar Me.sub.n --X.sub.m compounds containing X-groups with low or no carbon content, preferably Me-nitrates, solely or together with one or more metal salts of at least one iron group metal containing organic groups in at least one polar solvent with at least one complex former comprising functional groups in the form of OH or NR.sub.3, (R=H or alkyl). Hard constituent powder is added to the solution. The solvent is evaporated and remaining powder is heat treated in an inert and/or reducing atmosphere. As a result, coated hard constituent powder is obtained which after addition of a pressing agent can be compacted and sintered according to standard practice.