Ammonia-Precipitated Cu/Al2O3 Catalyst for the Highly Selective Gas phase Conversion of 1,4-Butanediol to Tetrahydrofuran

In this work, the influence of different precipitating agents on the physicochemical properties and catalytic performance of Cu/Al2O3 catalysts is systematically investigated.Compared with conventional precipitants (NaOH and Na2CO3), the copper-ammonia precipitation strategy enables controlled release of Cu2+ species via ammonia complexation, which in turn regulates the nucleation and deposition of copper species during catalyst synthesis.

As a result, the resulting catalyst exhibits a more ordered pore structure, higher copper dispersion, and stronger metal-support interactions, which optimizes surface acidity and improves catalytic performance. The catalyst prepared with aqueous ammonia exhibited the highest activity, achieving 100% complete BDO conversion and excellent THF selectivity as high as 99.5%. This work demonstrates that controlled precursor release via ammonia complexation offers an effective strategy for regulating pore structure development, copper dispersion, and metal-support interactions, providing a rational approach for the design of highly efficient Cu-based dehydration catalysts.