Kenneth G. Rappe

NO_x abatement from H₂ internal combustion engines (H₂-ICEs) is challenging due to high H₂O content and unburned H₂ in the exhaust.

Ce/Mn-oxide reduces the quantity and stability of NH₄NO₃ deposits in Cu-SSZ-13.

The objective of this project is to develop a strategy for the integration of catalytic NOX emission control and particulate matter emission control into a single device for the successful application to heavy-duty on-road diesel engine exhaust aftertreatment. The critical attributes of such a device, for successful application to PACCAR fleet, are as follows: 1. Must have sufficient filtration efficiency and successfully demonstrate soot management strategies (i.e., oxidation) to be economically attractive and regulatory compliant for particulate matter abatement. 2. In particular, the integrated device must retain sufficiently high soot oxidation capacity with NO2 (i.e., passive soot oxidation) across an applicable engine test cycle to be economically attractive. 3. Must exhibit sufficient catalytic NOX reduction activity in an economically-attractive fashion that is regulatory compliant. Wall-flow diesel particulate filter (DPF) technology has been successfully developed and deployed for particulate matter (PM) removal from engine exhaust.1-3 Thus, DPF technology will be the basis of PM filtration for this effort, and PM removal efficiency will not be a fundamental focus of study is this project. Selective catalytic reduction (SCR) technology employing base metal-exchanged zeolite has also been successfully developed and deployed for the abatement of oxides of nitrogen (i.e., NOX) from diesel enginemore » exhaust.4-8 Thus, SCR technology with base metal-exchanged zeolites will be the basis of NOX abatement for this effort. This project will develop a strategy for the integration of SCR and DPF technologies into a single device (herein referred to as SCRF) for the successful application to heavy-duty on-road diesel engine exhaust aftertreatment. The key technical accomplishments to be pursued in this work are as follows: 1. Integration of a DPF with a binary catalyst system consisting of an SCR phase and a selective catalytic oxidation (SCO) phase to enable sufficient passive soot oxidation capacity within the device. 2. The SCR-SCO binary catalyst system will be successful in enabling the availability of NO2 for achieving the necessary passive soot oxidation capacity within the integrated device while retaining high NOX reduction efficiency and minimizing the parasitic oxidation of NH3 (with O2). 3. Fundamental understanding of the interaction of the SCR and SCO catalyst phases will be achieved to lead to an optimized binary catalyst system, identifying the necessary engineering requirements and system limitations for their integration, with a view to proper function and optimal integration. 4. Develop the necessary understanding of aging and poisoning behavior of the binary catalyst system as it compares to current state-of-the-art SCR catalysts for determining the impacts of the SCO phase and mitigating of those that adversely impact aging behavior of the system. 5. Develop models that incorporate the SCRF catalyst system that can accelerate the optimization of the system by providing SCRF operational insight while simultaneously minimizing experimental testing. 6. Develop the necessary understanding to potentially lead to the design and optimization of 4-way devices, which will address PM, hydrocarbons, CO, and NOX in a single unit. « less

The CRADA between Cummins and Battelle will focus on: advanced emission control for high-efficiency engines. It will specifically focus on the following three areas: 1. Passive NOx absorbers - The purpose is to develop next generation materials that can be efficiently used to address the cold-operation, as driven by improved engine efficiency. 2. Oxidation of methane and short alkanes – The purpose is to address cold-operation emissions arising from CNG vehicles. 3. Improved understanding of particulates – The purpose is to understand how particulates are formed which will be used to develop strategies to address the tightening regulations and their enforcement for exhaust particulate matter. The first two areas will be based on PNNL’s technical leadership in the area of zeolite-based materials. The third area will have a shorter time scope to leverage the unique SPLAT capabilities at PNNL to help address Cummins’ needs in improving the understanding of particulates

The low temperature activity of zeolite-based SCR catalysts can be improved through incorporation of a metal oxide. The metal oxide catalyzes NO oxidation and prevents NH₄NO₃ deposits, while the zeolite phase provides NH₃ adsorption sites.

There is significant concern over the contributions of GHG emissions to global warming which has sparked intense focus on reducing GHG emissions in industrial processes. In response, this project aims to develop and demonstrate a methane oxidation catalyst that can be deployed on NG engines used in US O&G industry and will serve to significantly reduce the carbon footprint associated with those midstream operations. The catalyst will achieve 90% oxidation efficiency while operating at 450°C or less and at 50% less Pd versus existing catalyst technology. This technology would enable the realization of nearly 30% reduced GHG emissions from NG engines (versus diesel) that methane slip from these engines otherwise negates.

US automotive OEMs are required to meet the twin challenge of corporate average fleet fuel economy of 54.5mpg and stringent Bin30/SULEV30 emissions standards for light duty vehicles by 2025. This creates a heavy burden on the R&D community to discover and develop the necessary enabling technologies by 2023 to integrate into powertrain systems intended for 2025. Further amplifying the emissions challenge is the reduction in engine exhaust energy resulting from more fuel-efficient powertrains and the regulatory requirement of 15-year system performance. This forces aftertreatment systems to continue to push their operational limits to increasingly lower temperatures. This CRADA will focus on a broad and very important area of critical relevance to DOE and Stellantis, i.e., development of low temperature aftertreatment approaches, while not sacrificing durability.