Platinum Mesoporous Silica Catalysts for Liquid Media Oxidation

ABSTRACT

Mono- and bimetallic heterogeneous catalysts with mesoporous structure were prepared in two steps. In the first step, SBA-15 and amino-SBA-15 supports were prepared, and in the second, these materials were impregnated with Pt and Co precursors. High-surface-area supports like SBA-15 afford highly dispersed metal oxide species which are the key parameter in the rather difficult oxidation of alkenes with hydrogen peroxide. The obtained mesoporous catalysts with 0.1% Pt and 1% Co were characterized by nitrogen adsorption, ultraviolet–visible, Fourier-transform infrared, and X-ray absorption spectroscopies. X-ray absorption spectroscopy demonstrated the presence of Pt–oxygen for both Pt–SBA-15 and Pt–amino-SBA-15 samples, suggesting a higher number of oxidized platinum species in the second material. The adopted procedure was simple, green, and efficient for 3-butene-1-ol, cis-2-butene-1, 4-diol, and cyclohexene oxidation. The use of H₂O₂, a clean oxidant, is an important feature of a green chemical reaction since it produces only water as the by-product. The mesoporous structure of the silica-supported catalysts enables better accessibility of active sites to bulky substrate molecules, reflected in the high conversions and enhanced selectivity.

KEYWORDS:

• Liquid oxidation
• mesoporous silica
• nanomaterials
• platinum catalysts

Additional information

Funding

The work has been funded by the Romanian Ministry of Research and Innovation, under 34 N/2016 NUCLEU Program, Project PN 16 36 04 03 “Research on the development of new porous materials with high selective and catalytic properties for the reduction and stabilization of the pollutant concentrations in gaseous and liquid backgrounds.”