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Hydrocarbon conversions with some intermetallic catalysts
Author(s) -
Bahia A.,
Brown J. M.,
Caga I. T.,
Harris I. R.,
King C. E.,
Winterbottom J. M.
Publication year - 1990
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.280480310
Subject(s) - hydrogenolysis , intermetallic , catalysis , auger electron spectroscopy , methanation , chemistry , alloy , selectivity , alkene , hydrogen , quenching (fluorescence) , phase (matter) , inorganic chemistry , analytical chemistry (journal) , materials science , organic chemistry , physics , nuclear physics , quantum mechanics , fluorescence
The intermetallic pseudo‐binary alloys of the general type ZrRh 3‐x Pd x and ZrRh 3‐x Ru x (0 < × < 3) have been prepared by argon arc melting and melt quenching of the constituent elements. The alloys were powdered and employed as catalysts for (i) hydrogenation of oct‐1‐yne in the liquid phase at 101.32 kPa total pressure and 70°C, (ii) hydrogenation of buta‐1,3‐diene in the gas phase at 101.32 kPa total pressure in the temperature range 45–225°C, and (iii) hydrogenolysis of n‐pentane in the gas phase at 101.32 kPa total pressure and in the temperature range 200–400°C. Activity and selectivity measurements were made with respect to (i) alkene formation for the hydrogenation reactions, and (ii) C 2 + C 3 ‐alkane formation for the hydrogenolysis reaction. The activity of the alloy series appears to correlate to some degree with the electronic properties and hydrogen sorption capacity of the intermetallic alloys. Auger electron spectroscopy measurements revealed that for ZrRh 3‐x Pd x alloys both the surface and bulk compositions were in good agreement; this behaviour is contrasted briefly with that of CeRh 3‐x Pd x alloys which, unlike ZrRh 3‐x alloys, suffered significant oxygen interaction in the surface and sub‐surface layers, although this did not affect Rh:Pd ratios. Catalysts that were active for hydrogenation were inactive for hydrogenolysis and vice versa. However, selectivity values for the hydrogenation reactions generally reflected the behaviour of the predominant noble transition metal. Again, the behaviour of ZrRh 3‐x Pd x and CeRh 3‐x alloys is contrasted, since the latter were more selective for butene formation from buta‐1,3‐diene, and attributed to the oxygen Contamination of the surface. Further more, the selectivity of both ZrPd and CePd, for 1‐octyne and butu‐l j‐dene hydrogenation was significantly greater than that of palladium by virtue of the fact that the intermetallics were found to be largely inactive for alkene hydrogenation.