Premium
Activities and selectivities of copper/metal‐oxide catalysts at temperatures relevant to chemical heat‐pumps based on isopropanol/acetone interconversions
Author(s) -
Cunningham Joseph,
Hickey James N.,
Wang Zhenyi
Publication year - 1996
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/(sici)1099-114x(199609)20:9<763::aid-er190>3.0.co;2-j
Subject(s) - dehydrogenation , selectivity , acetone , chemistry , catalysis , endothermic process , copper , inorganic chemistry , exothermic reaction , oxide , ketone , copper oxide , atmospheric temperature range , metal , organic chemistry , adsorption , thermodynamics , physics
Abstract Results are presented concerning the possible suitability of various oxide supported copper catalysts for utilization in proposed chemical heat pumps, featuring isopropanol dehydrogenation as a ‘low’ temperature endothermic process coupled with acetone hydrogenation as a higher temperature exothermic process. For each of those processes, separate determinations have been made of the temperature ranges within which adequate levels of pseudo‐steady‐state activity and selectivity were maintained at vapour/solid interfaces over Cu/Al 2 O 3 , Cu/Cr 2 O 3 , Cu/SiO 2 and Cu/TiO 2 catalysts. For acetone hydrogenation over Cu/Al 2 O 3 and Cu/SiO 2 , that range extended over 423–550 K. However, over Cu/Cr 2 O 3 and Cu/TiO 2 it was restricted to 423–473 K, limited by insufficient activity at the lower end, and at the upper end by a fall‐off in selectivity caused by onset of acetone oligomerization to C 6 , C 9 and C 12 ketones. Similar temperature ranges were found to be necessary for attainment of adequate levels of activity and selectivity for dehydrogenation of isopropanol vapour over oxide‐supported copper catalysts. Again over Cu/TiO 2 materials, selectivity declined above 473 K owing to the formation of oligomeric ketone products. System modifications to overcome the indicated difficulties are briefly considered.