There has been a great deal of recent activity in the catalytic removal of NOx. This manuscript provides an analysis of the recent research methodology in this field, with a brief analysis of NOx reduction with hydrocarbons (vs. other reductants), the decomposition on NO into N-2 and O-2, and processes that do not produce NOx. Limiting features of the current catalytic approaches to NOx removal are discussed. The current effectiveness of recent catalytic NOx removal is assessed. Further, suggestions are offered to help future investigators focus on key experimental parameters and on opportunities for additional research that offer major societal and economic impact.