Efficient electrocatalysts for hydrogen evolution reaction (HER) in alkaline solution are highly required for water splitting. Here we design an ultra-small PtO_x nanoparticle with hybrid Pt chemical states on carbon nanotubes as highly efficient alkaline HER catalyst, which shows a low overpotential of 19.4 mV at 10 mA cm⁻², a high mass activity of 5.56 A mg_Pt⁻¹ at 0.1 V, and a stable durability for at least 20 h. The HER performance is better than that of the benchmark 20 wt% Pt/C while the Pt content in the catalyst is only about one tenth of that in Pt/C. It also represents one of the best catalysts ever reported for HER in alkaline solution. Synchrotron radiation X-ray absorption spectroscopy reveals that the efficient and stable alkaline HER performance can be attributed to the favorable design of hybrid chemical states of Pt with carbon nanotubes, which exhibits abundant surface Pt−O as active catalytic sites and forms stable Pt−C interfacial interaction to both anchor the NPs and improve the synergistic effect between catalyst and substrate.

分解水非常需要在碱性溶液中用于氢生成反应（HER）的高效电催化剂。在这里，我们设计了一个超小型的PtO _X上的碳纳米管的纳米颗粒与铂的混合化学状态为高效率的碱性催化剂HER，其示出了低的超电压19.4毫伏在10mA厘米^-2，5.56甲毫克的高质量活性_的Pt ^{- 1个}在0.1 V电压下，至少20小时具有稳定的耐久性。HER性能优于基准20 wt％Pt / C，而催化剂中的Pt含量仅为Pt / C的十分之一。它也代表了有报道的碱性溶液中HER最好的催化剂之一。同步辐射X射线吸收光谱表明，有效而稳定的碱性HER性能可归因于Pt与碳纳米管混合化学态的良好设计，该碳纳米管具有丰富的表面Pt-O作为活性催化位点并形成稳定的Pt-C界面相互作用既可固定NP，又可提高催化剂与底物之间的协同作用。