An effective cation exchange strategy is developed to synthesize highly dispersed palladium (Pd) nanoparticle (NP)–embedded mesoporous TiO₂ nanospheres enriched with oxygen vacancies aiming at overcoming the specific service condition and stability limitations of supported metal electrocatalysts. This strategy involves embedding Pd²⁺ cation into the interlayer of sodium titanate sheets through cation exchange with Na⁺, followed by annealing to obtain metallic Pd NP–embedded anatase phase TiO₂ (Pd–TiO₂). The resulting Pd–TiO₂ shows excellent electrocatalytic activity toward hydrogen evolution reaction (HER) (i.e., an overpotential of 108 mV at 10 mA cm⁻²) with good stability in acidic media, along with good activity and excellent stability under basic and neutral conditions. The high HER activity is attributed to the uniform distribution and strong attachment of Pd NPs in the TiO₂ nanospheres, the high porosity of mesoporous TiO₂ nanostructures, and the creation of oxygen vacancies in TiO₂ induced during the cation exchange process. Our findings are supported by the density functional theory calculations, which demonstrate the synergistic effect between Pd and TiO₂ and the contribution of oxygen vacancies to the high HER performance.

开发了一种有效的阳离子交换策略，以合成富含氧空位的高度分散的钯（Pd）纳米粒子（NP）嵌入的介孔TiO ₂纳米球，旨在克服特定的使用条件和负载型金属电催化剂的稳定性限制。该策略包括通过与Na ^+的阳离子交换将Pd ²⁺阳离子嵌入钛酸钠板​​的中间层，然后退火以获得金属Pd NP嵌入的锐钛矿相TiO ₂（Pd-TiO ₂）。生成的Pd-TiO ₂对氢气析出反应（HER）表现出出色的电催化活性（即，在10 mA cm ^-2时的过电势为108 mV）在酸性介质中具有良好的稳定性，以及在碱性和中性条件下的良好活性和优异的稳定性。较高的HER活性归因于Pd NP在TiO ₂纳米球中的均匀分布和牢固附着，中孔TiO ₂纳米结构的高孔隙率以及在阳离子交换过程中在TiO _2中引起的氧空位的产生。我们的发现得到了密度泛函理论计算的支持，这些计算证明了Pd和TiO ₂之间的协同作用以及氧空位对高HER性能的贡献。