STI FRAMEWORK PROGRAMME
"Platinum nano" - Platinum as an essential element in an integrated process for efficient energy conversion

07 August 2017

Project coordinator:

Eric van Steen

University of Cape Town, Department of Chemical Engineering

South Africa

Project partners:

Antônio José Roque da Silva

Brazilian Synchrotorn Light Laboratory

Brazil

Ankur Bordoloi

CSIR-Indian Institute of Petroleum

India

Funding agencies:

CNPq (Brazil), DST (India), NRF (South Africa)

 


The conversion of biomass into liquid fuels and power is important for development of amongst others rural areas, which are not well connected to the urban centers around the world. For instance, in Central Africa more than 2/3rd of the population does not have access to power hampering the economic development of these regions. Also, India and Brazil face challenges in both power and liquid fuel supply. The ability to create power in conjunction with production of liquid fuels on a local scale is attractive for these regions, but would require robust processes, such as the conversion of biomass to synthesis gas, which can subsequently by converted to liquid fuels with the off gas being used for the generation of power in a so-called co-generation mode (in this proposal using a fuel cell). This process is rather expensive, but may become cheaper by decreasing the cost of synthesis gas generation (by changing the feed from oxygen to air and by changing the process from auto-thermal reforming to aqueous phase reforming). 

The resulting, overall process utilizes platinum as an essential element in the catalyst of the various process steps, viz. as a (promoted) catalyst in aqueous phase reforming, as an essential promoter in cobalt-based Fischer-Tropsch catalyst and of course as the electro-catalyst in the fuel cell, and understanding the role platinum plays in these processes may increase its efficient usage.    

The role of water in aqueous-phase reforming is studied using model compounds (RSA) and using realistic feedstock (Indian). The stability of the platinum-based catalyst may be enhanced by modifying the surface with Bi-O-linkages, whose existence may be shown to be present using XAS (Brazil).

The Fischer-Tropsch synthesis has to be performed at high levels of conversion, and an active catalyst is required. Platinum promoted cobalt catalysts have been shown to be intrinsically more active, which may be ascribed to alloying effects. The Fischer-Tropsch synthesis will be carried out at the required conditions operating with a variety of feedstocks (India/RSA); the surface alloying will have probed using XAS (Brazil).

Power can be generated using fuel cells, but the efficiency is reduced due to the slow oxygen reduction rate. The efficiency may be improved by modifying the edges of the nano-particles with elements such as Ag and Au (RSA) resulting in a kinetic connection between Pt(100) and Pt(111). The efficiency of modifying the edges of nano-particles with noble metals would be probed using XAS (Brazil).