Does commercial bread use baking powder?
No way. I have 3 loaves of (different brands) commercial bread open at home now. None of them lists baking soda, baking powder, sodium bicarbonate or any other synonym I know of, and all three do list "yeast". In addition, Amazon website gives the ingredient list for the authentic "Wonder Bread classic white bread loaf", and it also calls out yeast, and not baking powder.