Abstract: The efficiency of dehydrogenation and that of hydrogenation are improved. A hydrogen generator for generating hydrogen by dehydrogenation of organic hydrides in the presence of a catalyst is characterized by comprising a reactor vessel (10) of a multi-tubular structure having a region (12) for supplying fuel to generate heat necessary for dehydrogenation, the region containing a combustion catalyst for combusting fuel, and a region (11) containing a dehydrogenation catalyst necessary for dehydrogenation, the regions being arranged radially side by side with a wall separating them.

Abstract: The efficiency of dehydrogenation and that of hydrogenation are improved. A hydrogen generator for generating hydrogen by dehydrogenation of organic hydrides in the presence of a catalyst is characterized by comprising a reactor vessel (10) of a multi-tubular structure having a region (12) for supplying fuel to generate heat necessary for dehydrogenation, the region containing a combustion catalyst for combusting fuel, and a region (11) containing a dehydrogenation catalyst necessary for dehydrogenation, the regions being arranged radially side by side with a wall separating them.

Abstract: A catalyst comprising a combination of rhodium, iridium and lithium supported on a carrier having a specific surface area of more than 150 m.sup.2 /g is disclosed for producing two carbon atom oxygenerated compounds from carbon monoxide. The catalyst has high catalytic activity and high selectivity to acetic acid.

Abstract: A rhodium catalyst containing supported rhodium metal omnipresent in the surface layer or in the neighborhood of the surface layer of the particles of a silica or titania type support is presented. This catalyst is prepared by a method (i) in which the support is dipped into an aqueous solution of a water-soluble rhodium salt previously adjusted to pH of at least 10, followed by the drying and reduction, or a method (ii) in which the support is first dipped into an aqueous solution of a water-soluble rhodium salt having a pH of 1 or less and, then, dipped into an aqueous alkaline solution containing an alkaline compound in an amount sufficient to neutralize the acid impregnated in the support and also sufficient to convert the rhodium salt impregnated in the support into rhodium hydroxide, followed by the drying and reduction.

Abstract: A rhodium catalyst containing supported rhodium metal omnipresent in the surface layer or in the neighborhood of the surface layer of the particles of a silica or titania type support is presented. This catalyst is prepared by a method (i) in which the support is dipped into an aqueous solution of a water-soluble rhodium salt previously adjusted to a pH of at least 10, followed by the drying and reduction, or a method (ii) in which the support is first dipped into an aqueous solution of a water-soluble rhodium salt having a pH of 1 or less and, then, dipped into an aqueous alkaline solution containing an alkaline compound in an amount sufficient to neutralize the acid impregnated in the support and also sufficient to convert the rhodium salt impregnated in the support into rhodium hydroxide, followed by the drying and reduction.