Session: 05-03: NOx Control for Alternative Fuels

Paper Number: 172440

172440 - Intra-Catalyst Study of Fuel Contaminants on Light-Off Scr Catalyst Functionality 

Abstract: 

A close-coupled SCR or light-off SCR (LO-SCR) located upstream of conventional emission control systems can significantly contribute to reducing NOx emissions during the cold start or low temperature operation. Biodiesel, a domestically produced fuel, can contain trace contaminants such as alkali metals (e.g. sodium, potassium), alkaline earth metals (e.g. magnesium, calcium), phosphorus, and sulfur. These impurities can deposit on and deactivate critical catalyst components, however, how the impurities impact catalysts is not well understood. Being the first catalyst element that is exposed to these metals, it is important to understand how these contaminants impact LO-SCR to either develop more resilient emissions control systems or to guide future fuel standards. This study aims to examine a series of engine-aged, vanadium base SCR (V-SCR) catalysts to elucidate the spatial distribution of biodiesel contaminants and the underlying mechanisms driving catalyst deactivation. The 100% biodiesel is doped with a combined total of 4ppm of sodium, potassium, and calcium to represent contamination effects. The engine-aged V-SCR catalysts were collected every two weeks over a 12-week period to assess the progressive impact of the metals. For analysis, Spaci-MS was used to evaluate spatial distribution of poisoning effect across the catalyst surface and compared to quantitative materials characterization data. This information will be utilized to develop models establishing the correlation between chemical contaminant exposure and long-term durability of the catalyst.

Presenting Author: Yensil Park Oak Ridge National Laboratory

Presenting Author Biography: Yeonshil Park has been at Oak Ridge National Laboratory (ORNL) since 2020 and she is a R&D Associate staff member in the Applied Catalysis and Emissions Research Group. Her background is in aerosol science and her research was in a wide range of topics including particle formation and growth, organic solar cells, emissions control and carbon capture. She is currently involved in a broad range of catalytic research, such as studying biodiesel poisoning in selective catalytic reduction (SCR), solid sorbent for CO2 capture, methanol reforming to dimethyl ether (DME), and low-temperature methane oxidation catalysts.

Authors:

Yensil Park Oak Ridge National Laboratory
Gurneesh Jatana Oak Ridge National Laboratory
Jonathan Willocks Oak Ridge National Laboratory
Hai-Ying Chen Oak Ridge National Laboratory
Michael Lance Oak Ridge National Laboratory
Todd Toops Oak Ridge National Laboratory