Abstract: A process for the conversion of hydrocarbons to hydrogen and one or more oxides of carbon, comprising contacting the hydrocarbon with steam and/or oxygen in the presence of a spinel-phase crystalline catalyst comprising a catalytically active metal. There is also described a method for making a catalyst suitable for the conversion of hydrocarbons to hydrogen and one or more oxides of carbon comprising adding a precipitant to a solution or suspension of a refractory oxide or precursor thereof and a catalyst metal-containing compound to form a precipitate which is calcined in an oxygen-containing atmosphere to produce a crystalline phase with a high dispersion of catalyst metal. There is further described a crystalline catalyst comprising the elements nickel, magnesium, aluminium and a lanthanide element, in which the crystalline phase is a spinel phase.