Microkinetic Study of Oxygenate and Hydrocarbon Formation from Syngas on Rhodium and Cobalt Surfaces: Effect of Site Structure on Catalytic Cycles

	Clean Technology 2010 Chapter 1: Oil, Gas, Clean Coal & Nuclear
	Microkinetic Study of Oxygenate and Hydrocarbon Formation from Syngas on Rhodium and Cobalt Surfaces: Effect of Site Structure on Catalytic Cycles
Authors:	N. Kapur, C. Sampara, X. Hao, J. Hyun, B. Shan, J.B. Nicholas, B. Davis, K. Cho
Affilation:	Nanostellar Inc., US
Pages:	29 - 32
Keywords:	Fischer-Tropsch, microkinetics, Rhodium, Cobalt, defects, DFT
Abstract:	Syngas reformation into fuels is an attractive opportunity to diversify away from petroleum and address energy-dependency concerns. Rh and Co-based catalysts used within Fischer-Tropsch (FT) process selectively convert syngas into oxygenates and hydrocarbons respectively but suffer from catalytic activity issues. High CO conversion has been reported for large Rh and Co nanoparticles accompanied by variations in methanol, ethanol, and methane formation rates. Increase in CO turnover frequency has been attributed to an increase in surface step density. Insights into FT reaction network, structure-reactivity and structure-selectivity correlations required for catalyst design are however, lacking. Herein, we validate FT reaction networks on Rh and Co surfaces with theoretical and experimental efforts and investigate active site requirements. Microkinetic models are used to investigate competitive routes for forming oxygenates and hydrocarbons on both flat and stepped Rh and Co surfaces. Direct CO dissociation is promoted on defect sites and an alternative hydroxymethylene based route is kinetically favored on flat surfaces for both materials. Methylene addition to R-CH2 and CO is deduced to be the precursor for hydrocarbon and C2 oxygenate formation respectively. Our results indicate that catalytic routes are preferred on step sites irrespective of the reaction considered. Thus, further modifications to undercoordinated sites can lead to improvements in both activity and desired product selectivity.
ISBN:	978-1-4398-3419-0
Pages:	482
Order:	Online/Mail/Fax Ordering Options
Indexes:	Keywords, Authors, Affiliations
Up

Join Us

Featured Events

ARPA-E Energy Innovation Summit
Washington DC, Feb. 27-29, 2012

Cleantech 2012
(joint with TechConnect World)
Santa Clara CA, June 19-21, 2012

"We've very much enjoyed being a member of CTSI. In addition to the many networking and conference opportunities, we've found the monthly newsletters to be the best consolidated source of clean technology industry information and updates on policy, grants and market intelligence."

- Patrick J. Piper, QM Power, Inc.

"Ener-G-Rotors is pleased to be a member of CTSI. CTSI has been very supportive of our efforts in clean technology, helping to connect us with key legislators, introducing us to contacts at the DOE, and providing opportunities to network with other clean technology companies."

- Michael Newell, Ener-G-Rotors, Inc.

"The Clean Technology and Sustainable Industries Organization brings together the world's most innovative companies to provide critical thinking and technology solutions to real-world challenges."

- Dr. Ray O Johnson, Senior Vice President and Chief Technology Officer, Lockheed Martin

Clean Technology 2010

Chapter 1: Oil, Gas, Clean Coal & Nuclear

Microkinetic Study of Oxygenate and Hydrocarbon Formation from Syngas on Rhodium and Cobalt Surfaces: Effect of Site Structure on Catalytic Cycles