Postgraduate Seminar Presentation : Exploration and Rational Design of Pt supported catalysts for C3H8 dehydrogenation

Speaker Sajjad Rimaz (Supervsior(s): A/Prof Sibudjing Kawi and Dr Armando)

Host Department of Chemical and Biomolecular Engineering

Date/Time 03 Oct - 03 Oct, 4.00pm

Venue E5-02-32 , Faculty of Engineering, National University of Singapore

Synopsis

Propylene is the second most important starting product in the petrochemical industry and acts as a raw material for a variety of products such as polypropylene, acrylonitrile, propylene oxide etc. Although the major source of propylene is naphtha cracking, direct dehydrogenation of propane (PDH reaction) to form propylene has recently taken up a significant share of industrial propylene production. Because of the endothermicity nature of the reaction, it requires high reaction temperatures to achieve economically attractive yields. High reaction temperature causes cracking, and hydrogenolysis, which results in the formation of coke.
 
Supported platinum based catalysts are highly active for PDH while susceptible to deactivation by the formed coke. It is so common to add second metal to modify properties of Pt. Second metal acting as spacer (1) or formation of ensembles of a favourable size (shape effect), poisons acidic sites of the support, and changes the electronic environment of Pt. All of these, modifies properties of Pt and leads to decreases of the coke formation. As a result, the stability and selectivity of the catalyst will be improved: tin, zinc, and copper have been use a lot for this purpose. There are lack of data about effects of semi metals, Boron, Germanium, and Antimony on platinum for light alkane dehydrogenation. We are working on development and modification of platinum by semi metals to make it more thermally stable and carbon-resistant. Different characterization technics, such as FTIR, XPS, NH3-TPD, RAMAN, TGA, are used to characterize the catalyst. The catalytic performance of some of the prepared catalyst was checked in a fixed-bed reactor, and excellent performance [55% conversion (thermodynamic equilibrium conversion), 97% selectivity] was obtained.

Biography