Showing papers by "Jacob A. Moulijn published in 1985"
TL;DR: In this article, it was shown that temperature-programmed reduction (TPR) is a sensitive technique for the characterization of Co and Co-Aloxidic phases in CoOAl2O3 catalysts.
611 citations
TL;DR: In this paper, a consistent interpretation of the complex TPR results is constructed, in which the extent of H/sub 2/ dissociation catalyzed by low-valent Mo atoms plays a central role.
Abstract: The reduction of MoO/sub 3/ and MoO/sub 2/ is studied by temperature-programmed reduction (TPR). TPR patterns appear to be highly dependent on H/sub 2/O content of the reducing mixture, sample size, precalcination temperature, and heating rate. Activation energy values for reduction have been calculated from TPR series with various heating rates. A consistent interpretation of the complex TPR results is constructed, in which the extent of H/sub 2/ dissociation catalyzed by low-valent Mo atoms plays a central role. The formation of these Mo catalytic sites is found to depend on H/sub 2/O pressure, concentration of surface defects, and surface area. Reduction of MoO/sub 3/ to MoO/sub 2/ and of MoO/sub 2/ to Mo metal both can be catalyzed, in which case the rate-determining step is either H/sub 2/ dissociation, when the formation of catalytic sites is limited, or Mo-O bond breaking, when excess catalytic sites are present. Reduction of MoO/sub 3/ to MoO/sub 2/ can also take place noncatalyzed, with oxygen diffusion as rate-determining step. MoO/sub 2/ and Mo metal are also formed, as intermediates, in temperature-programmed sulfiding (TPS) of MoO/sub 3/. MoO/sub 2/ production is faster in H/sub 2//H/sub 2/S than in H/sub 2/ due to a different reductionmore » mechanism involving H/sub 2/S as primary reactant. The formation of Mo metal is also faster, due to a higher porosity of the MoO/sub 2/ formed in situ. 48 references, 13 figures, 1 table.« less
214 citations
TL;DR: In this article, temperature-programmed reduction (TPR) gives new information on the reducibility of CoOMoO3Al2O3 catalysts.
108 citations
TL;DR: In this paper, temperature-programmed reduction (TPR) has been applied to characterize the reducibility of Al2O3, SiO2-, and carbon-supported Re2O7 catalysts, over a wide range of transition metal content.
74 citations
TL;DR: In this paper, temperature-programmed sulfiding of CoO Al 2 O 3 catalysts has been studied by means of TPS, which gives information on the presence of several oxidic Co phases.
60 citations
TL;DR: In this paper, a series of temperature-programmed reduction (TPR) experiments with various heating rates have been used to calculate the activation parameters for the reduction of ReO 3, NH 3 ReO 4 and Re 2 O 7 /Al 2 O 3 catalysts.
20 citations
TL;DR: The effect of combustion temperature and coal rank on the organic composition of the off-gas was investigated in this article, where 120 hydrocarbons were found, of which over 80% have been identified.
4 citations