(7et) Modification of Nickel-Based Catalysts for the Dry Reforming of Methane By Atomic Layer Deposition

Littlewood, P. - Presenter, Northwestern University
Liu, M., Northwestern University
Weitz, E., Northwestern University
Schwietzer, N. M., Northwestern University
Marks, T. J., Northwestern University
Stair, P. C., Northwestern University
Economical methods of obtaining valuable products from low-value, small-molecule streams, such as methane and carbon dioxide, are required to diversify feedstocks and improve industrial scale efficiencies in the transition to cleaner fuels and chemicals. The majority of methane activation for chemicals production occurs through syngas routes and dry reforming of methane with carbon dioxide (DRM) is one which has traditionally been a challenge for catalyst design, due to the propensity of the catalyst to coke, sinter or otherwise deactivate in the harsh reaction environment.

In this work a range of standard, model, inverse and commercially available nickel-based catalysts have been synthesised and modified using Atomic Layer Deposition (ALD). Chemisorption and reaction studies are used with spectroscopic and x-ray techniques to understand the effects of changes in the overcoat layer on catalytic activity. Depositing a thermally stable but catalytically inactive metal oxide such as alumina blocks part of the available metal surface, reducing the initial activity but dramatically improving stability. This preserves both the nickel particle size and the chemical environment of the active site. Furthermore, the role of catalytically inert phases formed under high temperature oxidizing conditions is elucidated. Additional studies explore the effect of ALD layer synthesis conditions and composition on the overcoat layer and catalysis.

Research Interests:

I am particularly interested in the synthesis of model heterogeneous catalytic materials and their characterisation through advanced sorption or reaction engineering techniques in combination with kinetic modelling and vibrational spectroscopy. By determining structure-function relationships of well-defined heterogeneous catalysts, rational design of new systems and optimisation vectors for real-world catalysts and processes can be conceived and tested on the lab scale. Whilst I am primarily interested in hydrocarbon conversion chemistry, I believe these principles apply universally to any area of heterogeneous catalysis. I would like to achieve these aims in part by modifying existing inexpensive materials using new, scalable techniques for improved functionality.

Teaching Interests:

Core chemical engineering courses, in particular transport phenomena, catalysis, kinetics and thermodynamics.