A Hybrid Co Quaterpyridine Complex/Carbon Nanotube Catalytic Material for CO Reduction in Water.

Associating a metal-based catalyst to a carbon-based nanomaterial is a promising approach for the production of solar fuels from CO . Upon appending a Co quaterpyridine complex [Co(qpy)] at the surface of multi-walled carbon nanotubes, CO conversion into CO was realized in water at pH 7.3 with 100 % catalytic selectivity and 100 % Faradaic efficiency, at low catalyst loading and reduced overpotential. A current density of 0.94 mA cm was reached at -0.35 V vs. RHE (240 mV overpotential), and 9.3 mA cm could be sustained for hours at only 340 mV overpotential with excellent catalyst stability (89 095 catalytic cycles in 4.5 h), while 19.9 mA cm was met at 440 mV overpotential. Such a hybrid material combines the high selectivity of a homogeneous molecular catalyst to the robustness of a heterogeneous material. Catalytic performances compare well with those of noble-metal-based nano-electrocatalysts and atomically dispersed metal atoms in carbon matrices.