A series of ordered mesoporous silica (OMS) supported tantalum oxide samples (Ta/OMS) were tested as catalysts for the production of 1,3-butadiene (BD) from ethanol and acetaldehyde. To study the influence of the type of mesostructure, the pore size, and the particle morphology on the performance of the catalyst, Ta/OMS catalysts were prepared using two different mesostructured silica supports (2-D hexagonal SBA-15 and 3-D cubic KIT-6) and five different 2-D hexagonal OMS supports (SBA-15 series and MMS) with varied mesopore diameters in the range of 2.5-40.9 nm. The obtained Ta/OMS catalysts were characterized by a nitrogen physisorption analysis and X-ray diffraction, as well as by scanning electron micrography. The catalytic results showed that the pore size and crystal size of OMS samples are more important than mesopore structure such as pore dimension and pore shape to optimize the catalytic performance of Ta/OMS catalysts for BD production from ethanol and acetaldehyde. (C) 2014 Elsevier B.V. All rights reserved.