Chen Luyun, Li Chunlei, Liu Mengling, Dai Ziruo, Wang Haibin, Zhou Xuan, Zhao Qiuping, Cong Yuanyuan
School of Petrochemical Technology, Lanzhou University of Technology, Lanzhou, Gansu, 730050, China.
Key Laboratory of Low Carbon Energy and Chemical Engineering of Gansu Province, Lanzhou University of Technology, Lanzhou, Gansu, 730050, China.
Adv Sci (Weinh). 2024 Dec;11(48):e2410881. doi: 10.1002/advs.202410881. Epub 2024 Oct 25.
Effective hydrogen evolution reaction (HER) under high current density and enhanced hydrogen oxidation reaction (HOR) over a wide potential range remain challenges for Ru-based electrocatalysts because its strong affinity to the adsorbed hydroxyl (OH) inhibits the supply of the adsorbed hydrogen (H). Herein, the coexisting Ru─O─Ti and Ru─Ti bonds are constructed by taking TiO crystal confined flat-Ru clusters (F-Ru@TiO) to cope with above-mentioned obstacles. The different electronegativity (χ = 1.54 < χ = 2.20< χ = 3.44) can endow Ti in Ru─O─Ti bonds with more positive charge and stabilize Ru of Ru-Ti bonds with the low-valence. The strength of Ru─OH is then weakened by the oxophilicity of positively charged Ti in Ru─O─Ti bonds and the stronger Ti─OH bond could release active Ru, especially for low-valence Ru in Ru─Ti bonds, to serve as exclusive H sites. As expected, F─TiRu@TiO shows a low HER overpotential of 74 mV at 1000 mA cm and an ultrahigh mass activity (j) of 3155 A g for HOR. More importantly, F─Ru@TiO can tolerate the HER current density of 1000 mA cm for 100 h and the high anodic potential for HOR up to 0.5 V versus RHE.
对于钌基电催化剂而言，在高电流密度下实现高效析氢反应（HER）以及在宽电位范围内增强氢氧化反应（HOR）仍然是挑战，因为其对吸附羟基（OH）的强亲和力会抑制吸附氢（H）的供应。在此，通过采用TiO晶体限域的平面钌簇（F-Ru@TiO）构建共存的Ru─O─Ti和Ru─Ti键，以应对上述障碍。不同的电负性（χ = 1.54 < χ = 2.20 < χ = 3.44）可使Ru─O─Ti键中的Ti带有更多正电荷，并使Ru-Ti键中的Ru以低价态稳定。然后，Ru─O─Ti键中带正电的Ti的亲氧性会削弱Ru─OH的强度，而更强的Ti─OH键可以释放活性Ru，特别是Ru─Ti键中的低价态Ru，以作为唯一的H位点。正如预期的那样，F─TiRu@TiO在1000 mA cm时的HER过电位低至74 mV，HOR的超高质量活性（j）为3155 A g。更重要的是，F─Ru@TiO能够耐受1000 mA cm的HER电流密度达100小时，以及相对于可逆氢电极（RHE）高达0.5 V的HOR高阳极电位。
