Effect of catalyst preparation on catalytic activity

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:5500696

Huang, Y J.R.

Design parameters have been identified for Ni/Al{sub 2}O{sub 3} catalysts prepared by wet impregnation and incipient wetness from nickel nitrate solution in contact with a {gamma}-Al{sub 2}O{sub 3} support. The metal dispersion, activity for C{sub 1}, C{sub 2}, and C{sub 3} formation under synthesis conditions, and the carbon deposited during reaction have been shown to be predictable based solely on the properties of the electrolytes from which these catalysts were formed. Regardless of the method of preparation, NiAl{sub 2}O{sub 4} was found to be the only active Ni species on low weight loading Ni/Al{sub 2}O{sub 3} catalysts; both Ni and NiAl{sub 2}O{sub 4} are present on high weight loading catalysts. The high-temperature methane peak observed only from CO-TRP spectra of low weight loading catalysts is due to NiAl{sub 2}O{sub 4}; the low-temperature peak that appears as the weight loading is increased is due to Ni. Steady-state reaction kinetics for CH{sub 4} production yield activation energies which increase with increasing weight loading. The apparent activation energies for catalysts with a single methane peak in their CO-TPR spectra were found to be normally distributed. The apparent activation energies for catalysts with two methane peaks in their CO-TPR spectra were found to also be normally distributed when the method of preparation was considered in testing the statistical nature of the distribution. Titration experiments of the carbon pool subsequent to steady-state reaction of H{sub 2} and CO in conjunction with temperature-programmed surface reaction were used to asses the impact of Ni speciation on the rate-determining in step in the methanation reaction. In situ ESCA experiments and microreactor studies were used to examined the existence of metal-support interaction between dispersed Ni and the Al{sub 2}O{sub 3} carrier.

• Research Organization: Syracuse Univ., NY (USA)
• OSTI ID: 5500696
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010408* -- Coal
Lignite
& Peat-- C1 Processes-- (1987-)
ACTIVATION ENERGY
ALKANES
ALUMINATES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBON
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CONTROL
CORRELATIONS
DEPOSITION
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY
FISCHER-TROPSCH SYNTHESIS
HEAT TREATMENTS
HYDROCARBONS
HYDROGENATION
KINETICS
LOADING RATE
METALS
METHANATION
METHANE
NICKEL
NICKEL COMPOUNDS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
REDUCTION
SPECTROSCOPY
SYNTHESIS
TEMPERATURE CONTROL
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS