One-pot preparation of Ni-Cu nanoparticles supported on γ-Al2O3 as selective and stable catalyst for the Guerbet reaction of 1-octanol

Abstract

This paper reports on the “in-situ” preparation-deposition and reduction of Ni-Cu nanoparticles (NPs) on γ-Al2O3 as support, using a green and elegant one-pot synthesis approach. Pristine and supported Ni-Cu NPs were evaluated as (de)hydrogenation catalysts for the Guerbet reaction of 1-octanol and compared with a classic impregnated and “ex-situ” reduced NiCu on γ-Al2O3 catalyst. XRD reavealed that the degree of Ni-Cu nano-alloying was insignificant in the one-pot preparation method, resulting in Ni-Cu nanocomposites, while the degree of nano-alloying was resp. low and very high in the pristine nanoparticles (NPs) and the classic impregnated catalyst. The degree of reduction was very similar for both the in-situ and ex-situ reduction treatments of the supported catalysts as demonstrated by H2 chemisorption. The “in-situ” prepared supported Ni-Cu NPs showed an enhanced kinetics when compared to the unsupported pristine Ni-Cu NPs, showing a beneficial effect of the metal-support interaction, however the classic impregnated catalyst showed overall the best kinetics, selectivity and stability for the Guerbet reaction of 1-octanol.