In the high-temperature carbonization of the mixture of zeolite imidazolate framework(ZIF-8/ZIF-67) and heavy metal salts (Pt, Au salts), the ZIF structure will decompose and gas like CH4 will form and hence the weight of ZIF structure gets smaller, during this process, will the gas (CH4) carry the heavy metal like Pt and Au to fly away, in other words, the weight loss of heavy metals?