NEW APPROACH TO PREPARE HIGHLY DISPERSED NON-NOBLE (BI)METALLIC NANOPARTICLES SUPPORTED ON ORDERED MESOPOROUS SILICAS FOR CATALYTIC APPLICATIONS

摘要

Non-noble (bi)metallic supported nanoparticles (NPs) (e.g. Ni, Cu and Co-based) offer a range of technical and commercial advantages, which makes them a feasible alternative to the more expensive supported noble metal NPs (e.g. Pt, Pd, Ir, Au) catalysts. Consequently, over the last decade, an extensive research focused on the preparation methods and/or applications of (bi)metallic supported NPs as catalysts in various (de)hydrogenation processes involved in important fields such as fine chemistry, environmental pollution control, energy and so on. The unique properties of supported NPs are directly related to the specific particle morphology (size and shape), metal dispersion, concentration and the electronic properties of the metal within their host environment. Therefore, as compared to their bulk counterparts, greatly enhanced catalytic performances of the supported NPs (i.e., activities and selectivities) have been reported, which was explained by larger surface-to-volume ratios of NPs (i.e. higher dispersions) associated with an increased number of defect sites, kinks, steps, edges and corners. Furthermore, as compared with the monometallic counterparts, supported bimetallic NPs have proven to exhibit much improved catalytic performances, due to changes in the geometric and/or electronic properties of the main metal in bimetallic NPs, which are induced by the addition of the second metal (i.e., by ensemble and/or electronic effects).