• A binder- and carbon-free OER catalyst of a series of Co x Cu 1-x alloys is developed. • The role of composition controlling and electronic perturbation on OER performance is investigated. • The catalyst reconstruction process, during OER, is investigated. • Surface oxygen containing substances not only promote the activity of Co x Cu 1-x alloys, but also increase the durability. • The role d-band center shifting on OER activity of Co x Cu 1-x alloys is captured. The design of high efficiency, low cost and abundant sources electrocatalysts for oxygen evolution reaction (OER) has attracted more and more attention, because of the depletion of precious and rare metals. Herein, we reported a highly active Co 0.7 Cu 0.3 alloy, which screening from a series of Co x Cu 1-x alloys (x = 0.1–0.9) via surface composition controlling and electron state modification. Compared with the Co, other Co x Cu 1-x alloys, as well as commercial RuO 2 /IrO 2 , the Co 0.7 Cu 0.3 catalyst exhibited very high activity in electrocatalytic O 2 production from alkaline solution (∼207 mV overpotential). Meanwhile the Co 0.7 Cu 0.3 catalyst exhibited excellent durability for OER, after 72,000 s operation, the attenuation rate of Co 0.7 Cu 0.3 catalyst is lower than ∼ 20%. The high catalytic activity of Co 0.7 Cu 0.3 is attributed to positive shift of d-band center and surface species of Co 0.7 Cu 0.3 alloy which facilitates oxygen-containing species (OCS) formation (*H 2 O 2 , *OOH, *OH) and electron transfer. This method of improving the catalytic performance by adjusting the alloy composition to achieve the microscopic electronic perturbation effect is expected to attract attention in the later research.