Commercial nickel nanoparticles (Ni NPs) were directly converted to efficient electrocatalysts for CO2 reduction by urea–Ni solid powder pyrolysis, in which a Ni, N-co-doped graphite carbon shell wraps the Ni NPs in situ. 98.3% CO selectivity was realized with a current density of −20.2 mA cm−2 and an overpotential of 0.69 V.