UNIVERSITY

[I]    Research Trends

The group tunes research work to target synthesis, characterization and development of adsorbents and catalysts that are intimately related to industrial, energy, environmental and biological necessities. These are visualized in the research objectives set out below.

[II]  Research Objectives

1. Thermal genesis course of surface active solids:

• Decomposition course of various precursor compounds has been thermally, spectroscopically and microscopically examined to the onset of formation of  pure and composite nano- and microparticles of metal oxides.  Favourable surface texture, morphology, structure and catalytic activity of the end solid product have been the criteria adopted to assess the suitability of the precursor used and the thermal conditions applied. 

2. Temperature-programmed studies of gas/solid interactions:

• Active gas/solid surface and bulk interactions have been probed by TPR/TPO/TPD studies. Consequently, process parameters have been determined for the reductive and oxidative synthesis of metal and oxide catalysts and adsorbents. Moreover, energetics of chemisorption and desorption have thereby determined. Consequently, conditions of reductive synthesis of metal particles (eg., W, Fe, Co, ..etc) and dual-functioning catalytic sites on supported metal oxide (e.g., WOx ) species  have been determined.

3. Synthesis, characterization and development of industrially important catalysts:

• Chromia based catalysts:  In view of their potential activity in polymerization reactions (Philips Catalyst) and promised activity in redox reactions, these catalysts were prepared in various forms and extents of surface oxidation, and characterized for the surface chemical composition, structure and texture, using a wide range of spectroscopic and non-spectroscopic techniques and methods. The thermal stability of surface Cr(VI)-oxygen species generated on calcined chromia catalyst has received special attention, for their high volatility and proven detrimental impacts in the atmosphere, in order to alleviate reservations of environmentalists about their industrial application in combustion processes.

• Molybdena based catalysts: On the basis of their known HDS activity in petroleum refinery, these catalysts were prepared on various supports, in oxydic and sulfided forms, and examined for nature of the catalytically active sites, using spectroscopic and microscopic techniques. A special attention has been paid to the synthesis of molybdena/alumina catalysts via the solid/solid spreading method, in hopes of characterizing the interfacial steps involved.

• Manganese oxide based catalysts: The powerful redox activity, wide compositional range and various structural modifications of manganese oxides, have been the motivation of a number of investigations aiming at examining tunnel- and layer-structured Mn-oxides for possible shape selective catalytic applications in redox processes, and (b) developing Mn-oxide based H2O2-decomposition catalysts of  higher thermal stability suitable for use in adiabatic reactors (thrusters) of rockets and space crafts.

• Rhodium based catalysts: The gasoline-run automobile exhaust purifying performance of these catalysts has been the thrust behind our research endeavours to understand surface attributes of the oxidative degradation of the metal particles in CO atmosphere, and to devise a protective means against it.

4. Developing catalytic materials based on Group IVB metal oxides:

• Ceria, titania, hafnia and zirconia: The thermal genesis course and conduct of  these oxides in organic catalysis were thoroughly examined, using thermal, spectroscopic and chromatographic techniques. Moreover, their surface and catalytic chemistries toward ketones and saturated hydrocarbons revealed a distinct catalytic activity in combustion reactions, particularly for ceria.

• Zirconia: Polymorphic transitions of zirconia as a function of temperature and additives of acid radicals have been probed. The results obtained could reveal a strong link to exist between the surface structure of acid sites and the bulk crystalline modification of the oxide.

5. Developing solid acid and superacid catalysts:

• Phosphation and sulfation of metal oxides have been found to produce materials exposing strong Lewis and Bronsted acid sites. Ways of tailoring such materials with favourable proportions of these acid sites have been devised, and laboratory tests have revealed success in tuning catalytic selectivity in hydrocarbon reactions.

6. Advancing the application of in-situ infrared spectroscopy to adsorption and reactions at metal oxide surfaces – Towards molecular level understanding of adsorption and catalysis:

• Application of low temperature has been followed to improve adsorption on metal oxide surfaces of important probe molecules, such as CO. As a result characteristics of adsorption sites on these surfaces have been revealed. Moreover, catalytic interactions with metal oxide surfaces have been characterized by means of in-situ IR spectroscopic observation of catalytic interactions at gas/solid interfaces throughout the reaction course. Surface intermediates have been thereby characterized.

7. Recovery of catalytic materials from chemical waste:

• Iron oxide: Pigmentary iron oxide was successfully recovered from steel pickling chemical waste, which is accumulated in large amounts, neither properly utilized nor adequately dispensed, in local iron-and-steel factories. Adsorptive and pigmentary  properties were thoroughly examined, using surface-specific and other analytical techniques.

• Aluminium oxide: Catalytic alumina was successfully recovered from aluminium dross tailings accumulated in local aluminium manufacturing. A novel recovery route has been devised and patented. Also an ethene selective ethanol decomposition catalyst has been chemically made-up using the alumina thus obtained and the iron oxide recovered from the steel pickling waste. Ethanol is a major product of the Egyptian sugar-cane industrilization.

8. Revealing surface attributes of osteoporosis:

• The fact that bone osteoporosis is triggered at acid/bone interfaces of excessive activity has developed a research whereby the surface chemistry involved is to be revealed. Commercial and synthetic healthy and osteoporotic bone mimics have been examined by in-situ IR spectroscopic and microscopic studies in order to determine acid and humidity conditions underwhich the protective phosphate groups of hydroxyapatite are removed via hydrolytic interactions. Remedial attempts using MBP class of materials (phosphonates) and carbonation activity have also been assessed.

[III] Current and Future Research Activities

• Development of heterogeneous catalysts for biomass transformation into biofuel.

• Designing binary and ternary metal oxide composite heterogeneous and visible-light photocatalysts of decomposition activities.

• Developing soot oxidation catalysts making use of volatile oxydic species.

• Synthesis of high-temperature stable metal oxides of highly accessible surfaces for catalytic applications in natural gas combustion processes, using micro-emulsion and self-assemply nanotechniques.

• Designing cost-effective zirconia-supported metal and metal oxide catalysts for carbon oxide (CO,CO2) hydrogenation and methanation reactions.

• Examination of Biocompatible materials in search for surface attributes of osteoporosis.