Studies on Cu-exchanged small pore zeolites as selective catalytic reduction (SCR) catalysts
EMSL Project ID
60250
Abstract
To help meet the DOE goals of enabling more fuel-efficient vehicle engine technologies, we have been carrying out research programs funded by DOE/Office of Energy Efficiency and Renewable Energy (EERE)/Vehicle Technologies Office (VTO) for the past ~15 years, involving both collaborative CRADA programs with industries and fundamental programs directly funded by VTO. Currently, the industry-partner CRADA programs with Cummins, Inc. and PACCAR aim at (1) understanding gaps between accelerated laboratory aging and “real-world” aging of high-mileage commercial SCR catalysts; and (2) understanding how chemical poisons (e.g., sulfur from fuels, zinc and phosphorus from engine lubricants, and alkalis from biofuels) speed up catalyst degradation under realistic aging conditions. The program directly funded by VTO aims at developing a practically useful fundamental understanding of standard (4NO + 4NH3 + O2 = 4N2 + 3H2O) and fast (NO + NO2 + 2NH3 = 2N2 + 3H2O) SCR reaction mechanisms, site requirements, low-temperature constraints, and approaches to mitigate such constraints. For these programs to be successful, we rely on the use of a wide array of state-of-the-art catalyst characterization facilities in EMSL. Small-pore zeolites SSZ-13, SSZ-39 and high-silica LTA exchanged Cu catalysts will be investigated in their various aged forms. This project will also leverage other PNNL engine exhaust cleanup projects in understanding deactivation mechanisms of noble metal-based diesel oxidation catalysts (DOC), as well as passive NOx adsorber (PNA) materials. This proposal contains the following essential components: (1) synthesis of small-pore zeolite supports and Cu-exchanged zeolite SCR catalysts; (2) catalyst performance evaluation using our home-built plug-flow reaction systems with MKS gas-phase FTIR analyzers; (3) in situ/operando spectroscopic and microscopic characterizations, e.g., solid-state nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), X-ray photoelectron (XPS), Mössbauer and FTIR spectroscopies, scanning transmission electron microscopy (STEM), with EMSL support. Expected outcomes include 3-5 high impact journal publications, 3-5 national and international conference presentations and annual reports to DOE/EERE/VTO acknowledging the essential support from EMSL.
Project Details
Start Date
2021-10-27
End Date
2022-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members