Hafedh Driss

Hydrogen production by ammonia decomposition using high surface area Mo2N and Co3Mo3N catalysts

High surface area bulk molybdenum nitride catalysts were synthesized via temperature-programmed ammonolysis of an ammonium heptamolybdate and citric acid (CA) composite. The synthesized materials were tested for COx-free H2 production via ammonia decomposition for fuel cell application. Cobalt was added at different loadings (1, 3, and 5 wt%) as a promoter for the bulk molybdenum nitrides. The chemical composition and surface morphology of the nitride catalysts were studied by means of XRD, XPS, SEM-EDAX and TEM techniques. Addition of cobalt increased the formation of the γ-Mo2N phase and cobalt existed as the Co3Mo3N phase, which was uniformly distributed over Mo2N as evidenced by TEM and SEM analyses. A drastic increase in Mo2N crystal size was observed when the Co loading exceeded 3 wt%, which in turn decreased the catalyst activity for ammonia decomposition reaction. All catalysts exhibit higher activity than the reported nitride catalysts at low temperatures. All catalysts showed stable activity for 30 hours. The activation energy calculated for ammonia decomposition was decreased drastically from 131.2 to 99 kJ mol−1 by the addition of cobalt (1 wt%) in Mo2N preparation.

Partial oxidation of methanol over Au/CeO2–ZrO2 and Au/CeO2–ZrO2–TiO2 catalysts

Experimental data on hydrogen production via a partial oxidation of methanol (POM) reaction on Au/ZrO2, Au/CeO2–ZrO2 and Au/CeO2–ZrO2–TiO2 catalysts is presented in this article. The gold catalysts were prepared by a deposition–precipitation (DP) method and characterized by XRF, XRD, H2-TPR, XPS methods N2 adsorption. The activity results show that the catalyst containing 1 wt% gold supported on a CeO2–ZrO2 carrier demonstrates very good hydrogen selectivity and the highest catalytic activity among all tested catalysts. The optimal working temperature established was 375 °C. At this temperature 75.5% hydrogen selectivity was registered. The presence of oxidized gold in the catalysts composition as well as the support redox properties are the major factors controlling the observed catalytic activity.

Ammonia treated Mo/AC catalysts for CO hydrogenation with improved oxygenates selectivity

A series of ammonia treated Mo/Activated Carbon (AC) catalysts were synthesized by wet impregnation method by nominal incorporation of 5, 10 and 15 wt% of molybdenum. The calcined catalysts (

Studies on Au/Cu–Zn–Al catalyst for methanol synthesis from CO2

500{^{\circ }}\hbox {C}

Hydrogen generation by ammonia decomposition using Co/MgO–La2O3 catalyst: Influence of support calcination atmosphere

500∘C, 4 h,

Mild temperature palladium-catalyzed ammoxidation of ethanol to acetonitrile

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