substitution?

Leaveners are very important in a cake or baked goods, the only cake i know that doesnt need baking powder is angel food cake it uses eggwhite to aerate the cake and give volume to the cake,they are foam cakes or genoise.There are actually no substitute for baking powder and soda (actually there is one but im not sure if its readily available in baking department its baking ammonia or ammonium bicarbonate.