The invention relates to processes for preparing alkanolamines and ethyleneamines in the liquid phase, by reacting ethylene glycol and/or monoethanolamine with ammonia in the presence of an amination catalyst comprising one or more active metals selected from Sn and the elements of groups 8, 9, 10 and 11 of the Periodic Table of the Elements, wherein the amination catalyst is obtained by reductive calcination of a catalyst precursor. The catalyst precursor here is preferably prepared by contacting a conventional or catalytic support material with one or more soluble compounds of the active metals and optionally one or more soluble compounds of added catalyst elements. The present invention further relates to a process for preparing an amination catalyst comprising one or more active metals selected from Sn and the elements of groups 8, 9, 10 and 11 of the Periodic Table of the Elements, the amination catalyst being obtained by reductive calcination of a catalyst precursor, wherein the reactor in which the catalyst precursor is reductively calcined is connected to a denox plant, and to the use of a denox plant in the preparation of amination catalysts.