The sequential production of a library of N different solids, in particular heterogeneous catalysts, where N within a day is an integer of at least 2, is performed by a) producing at least two different sprayable solutions, emulsions and/or dispersions of elements and/or element compounds of the chemical elements present in the catalyst and optionally of dispersions of inorganic support materials, b) continuously metering the at least two different solutions, emulsions and/or dispersions in a predefined ratio into a mixing apparatus in which the solutions, emulsions and/or dispersions are homogeneously mixed, c) continuously drying the mixture removed from the mixing apparatus and recovering the dried mixture, d) changing the ratios in step b) and repeating steps b), c) and d) (N−1) times until N different dried mixtures are obtained, e) optionally shaping and optionally calcining the mixtures to give the solids.