Support induced phase engineering toward superior electrocatalyst

Abstract

The phase transformation of catalysts has been extensively observed in heterogeneous catalytic reactions that hinder the long cycling catalysis, and it remains a big challenge to precisely control the active phase during the complex conditions in electrochemical catalysis. Here, we theoretically predict that carbon-based support could achieve the phase engineering regulation of catalysts by suppressing specific phase transformation. Taken single-walled carbon nanotube (SWCNT) as typical support, combined with calculated E-pH (Pourbaix) diagram and advanced synchrotron-based characterizations technologies prove there are two different active phases source from cobalt selenide which demonstrate that the feasibility of using support effect regulating the potential advantageous catalysts. Moreover, it is worth noting that the phase engineering derived Co3O4-SWCNT exhibits a low overpotential of 201 mV for delivering the current density of 10 mA/cm2 in electrocatalytic oxygen evolution reaction (OER). Also, it reaches a record current density of 529 mA/cm2 at 1.63 V (vs. RHE) in the electrocatalytic urea oxidation reaction (UOR), overwhelming most previously reported catalysts.