Applied Catalysis A: General, Vol.539, 19-28, 2017
Selective hydrogenation of 3-Hexyn-l-ol with Pd nanoparticles synthesized via microemulsions
In the study at hand we present a design strategy for novel catalysts which can be used for the selective hydrogenation of alkynes to alkenes. The design of the novel catalysts is based on two main ideas, namely (1) the synthesis of Pd nanoparticles via microemulsions and (2) the use of highly-ordered mesoporous silica with a 3-D pore network (FDU-12) serving as support. The nanoparticles are deposited on FDU-12 in two different ways. Firstly, we simply impregnated the support with a dispersion of the nanoparticles. The resulting catalyst was not selective at all; on the contrary, it fully hydrogenated our model alkyne, namely 3-hexyn-l-ol. Secondly, we synthesized the FDU-12 in the presence of the nanoparticles (in situ synthesis). In this case, we obtained one catalyst which performed as well as the Lindlar catalyst although the metal content was slightly lower and our catalyst contained no Pb. Another catalyst of the same series, prepared in the presence of another stabilizer, performed as well as the NanoSelect (TM) catalyst but at a 7 times higher metal content. For the sake of comparison we also impregnated FDU-12 via classical incipient wetness impregnation and again obtained a completely nonselective catalyst. Our results demonstrate that the in-situ synthesis has great potential as regards the development of novel catalysts. (C) 2017 Elsevier B.V. All rights reserved.