Being a suitable way for achieving the maximum efficiency of atoms, the atomically dispersed metals are playing an ever-increasingly important role in bridging heterogeneous and homogeneous catalysis. It is extremely challenging for dispersing metals in atomic-scales as the applicable high-loading catalysts for industry. The reducible and defective supports or metal surfaces are commonly chosen for anchoring the metals. We here report that atomically-dispersed but high-loading (15 wt%) metals were achieved by covalent-bonding to irreducible SiO2 (though silanol groups) which is realized by a simple urea hydrolysis assistant hydrothermal-deposition method. The Cu-O-Si bonding tailors the structural and electronic states of catalyst by maximum of atom efficiency and tuning electronic effects. The intrinsic performance of C=O hydrogenation was thus boosted by one- to two- orders-of-magnitude in comparison with impregnated and precipitated catalysts. The choices of metals include Cu, Zn, Ni, Co and Mn, showing potentials for a category of applied materials. (C) 2017 Elsevier Inc. All rights reserved.