Catalytic effects of copper on dibenzo-p-dioxin and polychlorinated dibenzo-p-dioxin generations using ab initio molecular orbital method

The roles played by copper in dibenzo-p-dioxin formation from the precursor phenol have been investigated using ab initio molecular orbital calculation, and the following catalytic roles of copper has been identified: (i) stabilization of the total energy owing to the absorption of phenol, (ii) reduction of oxygen-hydrogen bond strength in phenol, and (iii) reduction of steric effect of hydrogen atom in pre-dioxin. The catalytic effect of copper has been shown in terms of the smaller apparent activation energy. In the case of polychlorinated dibenzo-p-dioxins generation from precursor polychlorinated phenols, the catalytic roles (i), i.e., the stabilization of the total energy of precursor, would become even stronger. On the other hand, the catalytic roles (ii) and (iii) are unchangeable regardless of the existence of substituted chlorine atom.