A transient kinetic investigation of Ni-catalyzed methanation: Annual report
The most important objective of this research is to gain an insight into the nature of the main surface species involved during methanation and to develop an understanding of factors influencing the rate determining process. With this ultimate goal in mind, studies of the reaction pathways of oxygen (and oxygen containing surface species) have been conducted. From experiments carried out by adding water to the gas phase and switching between isotopes H/sub 2//sup 16/O, H/sub 2//sup 18/O and D/sub 2//sup 16/O, it was concluded that oxygen, once reacted to form water, does not apparently readsorb. However, hydrogen in the water molecule can be readily exchanged with hydrogen on the surface, perhaps by an Eley-Rideal type of mechanism. By following multiple transients of carbon and oxygen, simultaneously, during /sup 12/CO-/sup 13/CO switch experiments, it was found that the residence time (and hence the size of the precursor adsorbed species reservoir) of water is either equal to or greater than that of methane, depending upon the reaction conditions and the catalyst employed. Future experiments planned include transients by switching between /sup 16/O/sub 2/ and /sup 18/O/sub 2/ under reaction conditions. These experiments, along with those already carried out, will be able to focus on the long-debated issue in the literature about whether or not the most abundant reaction intermediate (MARI) during methanation is an oxygen containing species. Future experiments will also include studies on a series of Ni and Ru catalysts in order to understand the effect of initial carbon deposition on methanation.
- Research Organization:
- Pittsburgh Univ., PA (USA). Dept. of Chemical and Petroleum Engineering
- DOE Contract Number:
- FG02-86ER13624
- OSTI ID:
- 6307843
- Report Number(s):
- DOE/ER/13624-1; ON: DE87013944
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
METHANATION
CATALYSIS
CARBON 13
CATALYSTS
DEUTERIUM
NICKEL
OXYGEN
OXYGEN 18
REACTION INTERMEDIATES
RESEARCH PROGRAMS
WATER
CARBON ISOTOPES
CHEMICAL REACTIONS
ELEMENTS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
ISOTOPES
LIGHT NUCLEI
METALS
NONMETALS
NUCLEI
ODD-ODD NUCLEI
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
STABLE ISOTOPES
TRANSITION ELEMENTS
090121* - Hydrocarbon Fuels- Chemical Synthesis- (1976-1989)