Water as a cosolvent - Effective tool to avoid phase separation in bimetallic Ni-Cu catalysts obtained via supercritical antisolvent approach

•The water addition is a tool to change properties of Ni-Cu systems obtained by a SAS.•The Ni-Cu catalysts were investigated by X-ray diffraction, SEM and TEM.•The formation of the solid solution structure Ni1-xCux.

A series of Ni-Cu metal catalysts were synthesized using supercritical antisolvent (SAS) approach under conditions of controlled water content in the initial solution of precursors. It is shown that low content of water in methanol (up to 9 vol.%) helps to adjust the structure, texture and morphology of the obtained materials. The water additives promote the formation of carbonate phase that during further decomposition and reduction steps allows obtaining the solid Ni1‐xCux solution without phase separation. In particular the addition of 7 and more vol.% of water leads to the complete introduction of Cu into the Ni crystal lattice without formation of separate enriched phases of Ni or Cu.

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