Muhammad A. Daous

Experiences with the safe operation of a 2 kWh solar hydrogen plant

Abstract This paper describes a complete solar hydrogen research plant and outlines the safety aspects of its design and operation. The plant is part of a Saudi-German research cooperation program in the field of solar hydrogen production (HYSOLAR). It has been in operation since November 1989. Since then, over 1 MWh has been utilized to produce hydrogen without any major problem. Only two minor incidents occurred during this period and are reported in the paper. In the light of the experience gained during the operation of the plant, some recommendations regarding the safety aspects are presented. These are also applicable for larger plants based on similar technology.

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.

Role of Chemical Kinetics in the Heterogeneous Catalysis Studies

Abstract The paper presents shortly some of the important elements of the theory and of the practical applications of the kinetics of heterogeneous catalytic reactions. Discussed are some of the most important concepts of the kinetics of complex heterogeneous catalytic reactions, methodology of building kinetic models and mathematical treatment of experimental data, influence of heat and mass transfer, types of laboratory reactors, kinetics and nanosized catalysts and others. Examples for use of the kinetic studies for the development and application of industrial catalysts and modeling of industrial reactors are presented.

Re-dispersion of gold supported on a ‘mixed’ oxide support

The ability to reactivate, stabilize and increase the lifetime of gold catalysts by dispersing large, inactive gold nanoparticles to smaller nanoparticles provides an opportunity to make gold catalysts more practical for industrial applications. Previously it has been demonstrated that mild treatment with iodomethane (J. Am. Chem. Soc., 2009, 131, 6973; Angew. Chem. Int. Ed., 2011, 50, 8912) was able to re-disperse gold on carbon and metal oxide supports. In the current work, we show that this technique can be applied to re-disperse gold on a ‘mixed’ metal oxide, namely a mechanical mixture of ceria, zirconia and titania. Characterization was conducted to guage the impact of the iodomethane (CH3I) treatment on a previously sintered catalyst. Graphical Abstract

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 (

Silicon and Silicon-Related Surfaces for Biosensor Applications

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

Use of Intraparticle Mass Transfer Parameters as a Design Tool for Catalyst Pellets

500∘C, 4 h,