https://phys.org/news/2018-07-tiki-torches-soot-diesel-filters.html

"This study is part of an effort over many years in which we have discovered and developed low-cost catalysts for soot oxidation that are based on silica glass," said Paul McGinn, a co-lead author of the study and professor in the Department of Chemical and Biomolecular Engineering at Notre Dame.

McGinn and co-principal investigator Changsheng Su at Cummins Inc. developed a method to coat diesel particulate filters with a silica glass, which slowly releases potassium ions. The potassium acts as a catalyst, reducing temperatures required to initiate filter regeneration—or soot oxidation—for improved efficiency.