Showing papers by "John B. Moffat published in 2000"
TL;DR: In this paper, the properties of barium hydroxyapatite (BaHAp) for ion exchange with Pb2+, Cu2+, Zn2+, Cd2+ and Co2+ have been investigated, with particular emphasis on the former two cations.
46 citations
TL;DR: In the absence of tetrachloromethane (TCM) carbon dioxide is the principal product formed in the oxidation of propane on ceria, and the enhancement of conversion and selectivity to propene is dependent upon the presence of chlorine, in whatever form, in the surface region of the catalyst as mentioned in this paper.
26 citations
TL;DR: In the presence and absence of TCM, the principal products were CO and CO 2 and the selectivity to propylene was found to depend on the stoichiometry as mentioned in this paper.
Abstract: The oxidation of propane on nonstoichiometric calcium hydroxyapatites has been investigated in the presence and absence of tetrachloromethane (TCM) at 723 K. In the absence of TCM, the principal products were CO and CO 2 and the selectivity to propylene was found to depend on the stoichiometry. On addition of TCM to the feedstream, it was generally observed that the conversion of propane and the selectivity to CO 2 decreased with increasing time-on-stream, while the selectivity to propylene increased. Both the conversion and selectivities were dependent upon the partial pressure of TCM in the feedstream, the stoichiometry and time-on-stream. The role of chlorinated species is discussed.
16 citations
TL;DR: In this paper, the effects of increases in loading and the introduction of oxygen on NO reduction with ammonia in the presence and absence of O2 have been examined over copper salts supported on activated carbon and carbon black, which have been characterized by application of X-ray diffraction and scanning electron microscopy before and after use in the reduction process.
Abstract: The activities for NO reduction with ammonia in the presence and absence of O2 have been examined over copper salts supported on activated carbon (AC) and carbon black (CB) which have been characterized by application of X-ray diffraction and scanning electron microscopy before and after use in the reduction process. The beneficial effects of increases in loading and the introduction of oxygen are demonstrated. On the most active catalyst and under optimum conditions 100% reduction of the NO to N2 occurs at 180 °C and Cu, Cu2O and CuO on the catalyst are shown to be present at various stages of the preparation and reduction process with large crystallites of metallic copper detected on the AC catalyst of optimum loading. Deactivation and regeneration of the catalysts is also examined. A mechanism for the redox process is proposed.
11 citations