Abstract: A novel hydrocarbonylation, i.e., decarbonylation in the presence of hydrogen, is disclosed. By applying hydrodecarbonylation to a series of reactions, monocyclic aromatic hydrocarbons such as benzene can be obtained in high yield from polycyclic aromatic hydrocarbons or heavy oils containing such materials. Thus, the present invention provides a method of effective utilization of carbon sources.

Abstract: A reduction catalyst is disclosed. This catalyst comprises a naturally-occurring inorganic material which is a tuff consisting essentially of SiO.sub.2, Al.sub.2 O.sub.3 and H.sub.2 O containing 1-10% by weight of an alkali metal oxide and an alkaline earth metal oxide and has an X-ray diffraction pattern as shown in Table A or Table B. It is produced by depositing of the tuff metal ions selected from the group consisting of a metal belonging to Ib Group, IIb Group and VIII Group of Periodic Table, chromium, vanadium and manganese, followed by heat treatment, and repeating the same using different metal ions on each occasion. The catalyst is useful as a reduction catalyst for nitrogen oxides.