Regulators are suggesting that catalytic converters remove VOCs, but some disagree.  What insight could you share?

This is technically correct because if you have an automobile running that engine is taking in air and then the catalytic converter is actually eliminating VOCs.  But, the only VOCs it's eliminating are the ones that are predominantly coming from the gasoline that is being pushed through the engine.  On a relative basis to the volume of air in the surrounding atmosphere, it's almost immeasurable.