Atomic chemical environment of tungsten in coal: Implication for the evolution of the germanium coal deposits

•The nature of W-O complexes in Ge-rich coal is studied using DFT calculation.•Ethanol, phenol, catechol, acetic acid, and benzoic acid represent all hydroxyls.•Phenolic hydroxyls are more reactive relative to others hydroxyl groups.•Tungsten can form more stable complexes with hydroxyls relative to Ge.•The formation and redistribution model of the Ge coal deposit is proposed.