This contribution discusses the laboratory results and factory-scale drying of an organic monohydrate with therapeutic qualities. The crystal form instabilities of this monohydrate are discussed with respect to undesired dehydrated crystalline species and an IPA solvate. To reproducibly determine the end-of-drying while ensuring deliverable monohydrate is produced, a factory-scale drying scheme in which a dew-point hygrometer is used to measure the water content of the dryer vapor effluent online was shown to be effective. This online measurement technique obviates the need for repeated sampling from the dryer and is a low-cost alternative to near-infrared (NIR) spectroscopy monitoring systems. This novel factory-scale drying scheme was successful in determining the end-of-drying while ensuring preservation of the desired monohydrate for four 20−30 kg batches. Also, drying curves were produced from the recorded dew-point data by an iterative approach.
High-throughput and combinatorial approaches have been applied to the discovery of catalysts for selective low temperature CO oxidation/VOC removal using mixed CO/propylene feeds, and for the water-gas shift (WGS) reaction using real post-reformer feeds containing CO, CO 2 , H 2 O and H 2 . The screening approach was based on a hierarchy of qualitative and semi-quantitative primary screens for the discovery of hits, and quantitative secondary screens for hit confirmation, lead optimization and scale-up. For WGS, primary screening was carried out using scanning mass spectrometry. For CO oxidation and VOC removal, parallel IR thermography was the primary screen. Multi-channel fixed bed reactors equipped with imaging reflection FTIR spectroscopy or GC were used for secondary screening. Novel RuCoCe compositions were discovered and optimized for CO oxidation/VOC removal and the effect of doping was investigated for supported and bulk mixed oxide catalysts. For WGS, noble metal-free and Pt-doped CoFeRu mixed oxides as well as Pt on CeO 2 and Pt on CeO 2 /ZrO 2 were investigated and a new synergistic PtFeCe ternary composition was discovered. In these cases oxygen vacancies in the ceria lattice are believed to play a key role in the strong and synergistic Pt-Ce interaction. Alkaline metal doping was found to enhance the selectivity towards WGS by suppressing the unselective methanation side reaction and to increase the low temperature catalytic activity.
The catalytic oxidation of carbon monoxide to carbon dioxide is an important process used in several areas such as respiratory protection, industrial air purification, automotive emissions control, CO clean-up of flue gases and fuel cells. Research in this area has mainly focused on the improvement of catalytic activity at low temperatures. Numerous catalyst systems have been proposed, including those based on Pt, Pd, Rh, Ru, Au, Ag, and Cu, supported on refractory or reducible carriers or dispersed in perovskites. Well known commercial catalyst formulations for room temperature CO oxidation are based on CuMn2O4 (hopcalite) and CuCoAgMnOx mixed oxides. We have applied high-throughput and combinatorial methodologies to the discovery of more efficient catalysts for low temperature CO oxidation. The screening approach was based on a hierarchy of qualitative and semi-quantitative primary screens for the discovery of hits, and quantitative secondary screens for hit confirmation, lead optimization and scale-up. Parallel IR thermography was the primary screen, allowing one wafer-formatted library of 256 catalysts to be screened in approximately 1 hour. Multi-channel fixed bed reactors equipped with imaging reflection FTIR spectroscopy or GC were used for secondary screening. Novel RuCoCe compositions were discovered and optimized for CO oxidation and the effect of doping was investigated for supported and bulk mixed oxide catalysts. Another family of active hits that compare favorably with the Pt/Al2O3 benchmark is based on RuSn, where Sn can be used as a dopant (e.g. RuSn/SiO2) and/or as a high surface area carrier (e.g., SnO2 or Sn containing mixed metal oxides). Also, RuCu binary compositions were found to be active after a reduction pretreatment with hydrogen.
Catalysis plays a very important role in sustainable and green chemistry applications such as renewable resources for energy and fuels, waste recovery and recycling and low‐ or even zero‐emissions power plants, chemical production sites and vehicles. Emissions control and environmental protection are new challenges that call for novel and far more efficient catalysts to be developed in short time periods. In this chapter, examples of the application of high‐throughput methods to heterogeneously catalyzed green chemistries are discussed. High‐throughput and combinatorial catalysis is ideally suited for the discovery of novel noble metal and mixed metal oxide catalyst formulations for total combustion/ volatile organic compound ( VOC ) removal, emissions control from stationary and mobile sources (NO x abatement, CO oxidation, automotive three‐way catalysis) because simple gas‐phase feeds and product mixes allows for truly parallel detection and very high sample throughputs. Furthermore, these methods are advantageously applicable to multicomponent catalysts (e.g. mixed metal oxides, alloys) for selective oxidation, hydrogenation, dehydrogenation and refining, including desulfurization and denitrification. Additionally, improved fast analytical techniques are making it increasingly possible to perform high‐throughput experimentation on complex real plant or vehicle feeds. This chapter focuses on the primary screening of metal oxides for low‐temperature CO oxidation and VOC combustion using infrared thermography reactors and SCR DeNO x of wafer‐formatted catalyst libraries using scanning mass spectrometry.
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