Ventura, CA, United States
Ventura, CA, United States

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Synergized Platinum Group Metals (SPGM) catalyst system for TWC application is disclosed. Disclosed SPGM catalyst system may include a washcoat with a CuMn stoichiometric spinel structure and an overcoat that includes PGM, such as palladium (Pd) supported on carrier material oxides, such as alumina. SPGM catalyst system shows significant improvement in nitrogen oxide reduction performance under lean operating conditions, which allows a reduced consumption of fuel. Additionally, disclosed SPGM catalyst system also exhibits enhanced catalytic activity for carbon monoxide conversion. Furthermore, disclosed SPGM catalyst systems are found to have enhanced catalytic activity for fresh and aged conditions compared to PGM catalyst system, showing that there is a synergistic effect between PGM catalyst and CuMn spinel within the disclosed SPGM catalyst system which help in thermal stability of disclosed SPGM catalyst.


Synergized Platinum Group Metals (SPGM) catalyst system for TWC application is disclosed. Disclosed SPGM catalyst system may include a washcoat that includes stoichiometric CuMn spinel structure, supported on doped ZrO_(2), and an overcoat that includes PGM, such as platinum (Pt) supported on carrier material oxides, such as alumina. SPGM catalyst system shows significant improvement in nitrogen oxide reduction performance under lean and also rich operating conditions. Additionally, disclosed SPGM catalyst system exhibits enhanced catalytic activity for carbon monoxide conversion. Furthermore, disclosed SPGM catalyst systems are found to have enhanced catalytic activity compared to PGM catalyst system, showing that there is a synergistic effect between PGM catalyst, such as Pt, and CuMn spinel within disclosed SPGM catalyst system, which help in activity and thermal stability of disclosed SPGM catalyst.


The present disclosure provides an identification process which may employ various identification techniques on Zero platinum group metal (ZPGM) catalyst systems, in order to identify responsible materials for the formation of corrosion material, such as hexavalent chromium compounds. Identification analysis, such as X-ray diffraction analysis (XRD), X-ray fluorescence (XRF), and X-ray Photoelectron Spectroscopy (XPS) may be performed on various thermally treated ZPGM catalyst systems, such as in bare substrate, substrate with one type of ZPGM in washcoat, a substrate with one type of ZPGM in overcoat and substrate combination of ZPGM metals in both washcoat and overcoat. Results of identification analysis may show that regardless of metal catalyst (for example Ag, Cu, Ce), hexavalent chromium (Cr^(6+)) may be formed on aged catalysts systems, which may be due to the high concentration of chromium in substrate. Therefore, corrosion and production of hexavalent chromium may initiate from elements found in the substrate and not from elements within the ZPGM metal catalysts.


A diesel oxidation catalyst (DOC) system for the treatment of exhaust gas emissions, including oxidation of nitrogen oxides (NO), unburned hydrocarbons (HC), and carbon monoxide (CO) is disclosed. Fresh and hydrothermally aged Zero-PGM (ZPGM) DOC samples are prepared and configured with an alumina-based washcoat on ceramic substrate, overcoat including doped Zirconia support oxide, and impregnation layer of CuMn spinel of selected base metal loadings. Testing of fresh and hydrothermally aged ZPGM DOC system samples including CuMn spinel is developed to evaluate the performance of CuMn spinel active phase in oxidation CO, HC, and NO, as well as production of NO_(2). Key to improvement in light-off performance and NO oxidation is to have a diesel oxidation catalyst that is substantially PGM-free and available for a plurality of applications in lean burn engine operations.


Synergized platinum group metals (SPGM) oxidation catalyst systems are disclosed. Disclosed SPGM oxidation catalyst systems may include a washcoat with a CuMn spinel structure and an overcoat including PGM, such as palladium (Pd), platinum (Pt), rhodium (Rh), or combinations thereof, supported on carrier material oxides. SPGM systems show significant improvement in abatement of unburned hydrocarbons (HC) and carbon monoxide (CO), and the oxidation of NO to NO_(2), which allows reduction of fuel consumption. Disclosed SPGM oxidation catalyst systems exhibit enhanced catalytic activity compared to PGM oxidation systems, showing that there is a synergistic effect between PGM and CuMn spinel composition within the disclosed SPGM oxidation catalyst systems. Disclosed SPGM oxidation catalyst systems may be available for a plurality of DOC applications.


The influence of a plurality of support oxides on coating process for ZPGM catalysts is disclosed. ZPGM catalyst samples with washcoat on suitable ceramic substrate and overcoat including a plurality of support oxides are prepared including an impregnation layer of CuMn spinel or overcoat may be prepared from powder of CuMn spinel with support oxide. Testing of fresh and aged ZPGM catalyst samples is developed under isothermal steady state sweep test condition. Catalyst testing allows to determine effect of a plurality of support oxides on coating processes, TWC performance, and stability of ZPGM catalysts for a plurality of TWC applications. Stability of ZPGM-TWC systems may be improved by promotion of the activity of ZPGM materials incorporating support oxides. Improvements that may be provided by the combination of support oxides with ZPGM materials in the catalyst may lead to a most effective utilization of ZPGM materials in TWC converters.


Variations of coating processes of ZPGM catalyst materials for TWC applications are disclosed. The disclosed coating processes for ZPGM materials are enabled in the preparation of ZPGM catalyst samples according to a plurality of catalyst configurations, which may include washcoat and an overcoat layer with or without an impregnation layer, including CuMn spinel and doped Zirconia support oxide, prepared according to variations of disclosed coating processes. Activity measurements under isothermal steady state sweep test condition are considered under lean condition and rich condition close to stoichiometric condition to analyze the influence of disclosed coating processes on TWC performance of ZPGM catalysts. Different coating processes may substantially increase TWC activity, providing improved levels of NO, CO, and HC conversions and cost effective manufacturing solutions.


Process for manufacturing ZPGM catalysts systems that may allow the prevention of formation or the conversion of corrosion causing compounds, such as hexavalent chromium compounds, within ZPGM catalyst systems is disclosed. In one embodiment, disclosed ZPGM catalysts systems, may include metallic substrate, which may include alloys of iron and chromium, a washcoat and an overcoat. Disclosed manufacturing process may include a thermal decomposition of hexavalent chromium compounds which may allow the decomposition of such compounds into trivalent chromium compounds, and may also produce metallic catalyst, such as silver. Such conversion may prevent corrosion formation, such as red color corrosion within ZPGM catalyst system. An embodiment of the disclosed process may include a reducing agent, which may be present in exhaust conditions, which may convert hexavalent chromium compounds into trivalent chromium compounds as well as produce metallic catalyst, such as silver. Employing the disclosed manufacturing process may allow the production of ZPGM catalyst systems that may exhibit high activity and enhanced performance.


Present disclosure provides a novel process for optimization of Zero-PGM catalyst systems using metallic substrate. Deposition of a homogeneous and well-adhered layer of catalyst on the metallic substrate may be enabled by the selection of a washcoat loading resulting from variation of metal loadings. Characterization of catalysts may be performed using a plurality of catalytic tests, including but not limited to washcoating adherence test, back pressure test, inspection of textural characteristics, and catalyst activity. Optimization may be applied to a plurality of metallic substrates of different geometries and cell densities.


Sulfur tolerant oxidation catalysts with significant oxidation capabilities are disclosed. A plurality of catalyst samples may be prepared including ZPGM material compositions of YMnO_(3 )perovskite, Cu_(x)Mn_(3-x)O_(4 )spinel, and a combination of both, supported on doped Zirconia and cordierite substrate, and front zoned with sulfur getters of Pd, Ba acetate, and Ce nitrate. Testing of samples may be performed under standard and sulfated DOC conditions to assess influence of adding front zoned sulfur getters to ZPGM catalyst samples. Levels of NO oxidation and HC conversion may be compared, and resistance to sulfur and catalytic stability may be observed to determine ZPGM samples zoned with sulfur getter which may provide the most significant improvements in NO oxidation, HC conversion, CO selectivity, and resistance to sulfur for use in DOC applications.

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