Peter William Lednor

Monolithic ceramics and heterogeneous catalysts: honeycombs and foams

Abstract Recent advances have been made in research on ceramic monolithic catalyst supports, particularly on honeycombs and ceramic foams. In the case of honeycombs, cordierite is the most commonly applied composition, but alternative materials, such as SiC, are beginning to be used for demanding conditions. Typical catalytic applications of honeycombs include use as catalyst supports for the removal of gaseous or particulate emissions from combustion engines (gasoline and diesel), and for reducing nitrogen oxide emissions from power plants. Ceramic foams are used commercially for the filtration of molten meals, and are attracting increasing attention as catalyst supports due to high thermal stability, high porosity and increased tortuosity with respect to honeycombs.

The preparation of silicon oxynitride, Si2N2O, as a high surface area powder by reaction of silica with ammonia at 1100°C

The title reaction is found to occur with an amorphous, non-porous but high surface area form of silica; other silica phases, differing in crystallinity and porosity, give substantially lower degrees of nitrogen incorporation on reaction with ammonia.

The use of a high surface area silicon oxynitride as a solid, basic catalyst

High surface area silicon oxynitride is shown to be a basic catalyst through its ability to catalyse Knoevenagel condensations when suspended in toluene at 50 °C; the activity is due to the presence of surface nitrogen.

Recent developments in materials science as applied to catalysis

Abstract Materials science plays an important role in the field of applied catalysis. Recent developments have been made in research related to catalytic materials as applied to catalytic processes for oil refining, chemicals synthesis, natural gas conversion and environmental technology. Future development of catalytic materials will be required to enhance the performance of catalyst systems for application in catalytic combustion, synthesis gas manufacturing, lean burn auto emission control and paraffin alkylation and at the interface between homogeneous and heterogeneous catalysis.

Characterization of High Surface Area Silicon Oxynitrides

High surface area silicon oxynitrides have been prepared by nitrida- tion of silica with ammonia. Characterization by Fourier-transform infrared spectroscopy has allowed quantitative determination of hydroxyl, amido and imido groups. Data obtained by X-ray photoelectron spectroscopy show that the nitrogen is well distributed in the surface of the materials.

On the Stability of Mo 2 N During First-Stage Hydrocracking

An unsupported sample of Mo 2 N has been subjected to a first-stage hydrocracking test. The evolution of the HDS and HDN performance indicated a transformation of Mo 2 N into MoS 2 . This was substantiated by XPS and TEM, the latter technique showing that the transformation is limited to only a few surface layers.

Materials science: A driver for innovation in applied catalysis

This paper suggests that materials science is an important driver for innovation in applied catalysis. A wide range of catalytic materials is discussed in support of this thesis, with porosity as a common theme, and covering micro, meso and macro-porous materials. Applications of these materials ia also wide-ranging, covering processes for the manufacture of fine chemicals or petrochemicals, and in oil refining, natural gas conversion and environmental processes. Further improvements in the rate of innovation can be expected from new partnerships which are being formed, both at business and research levels.