Exploring simple and flexible methods to synthesize an oxygen reduction reaction (ORR) catalyst with high catalytic activity is of great significance for the large-scale application of fuel cells. Here we developed an intermetallic PdZn on a TiO_2−x NS support catalyst by a simple strategy for large-scale production through an impregnation process involving low temperature annealing. This electrocatalyst prepared by a simple and single step exhibited better ORR activities in both acidic and alkaline solutions at room temperature with a higher value of electrochemical active surface area (ECSA). The repeated square-wave potential cycling test at 80 °C over 10 000 cycles confirmed the durability of the catalyst. The fuel cell using the PdZn/TiO_2−x NS catalyst showed a high power density of 855 mW cm⁻², which exceeds that of the PdZn supported carbon catalyst. Also, the proposed catalyst showed excellent stability over more than 100 h in proton-exchange membrane fuel cell (PEMFC) performance. Thus, the proposed TiO_2−x NSs will be an alternative to a carbon support in future PEMFC technology. Furthermore, PdZn/TiO_2−x NSs also showed higher activity and stability for the glycerol oxidation reaction (GOR) and higher selectivity for glycerate production than PdZn/C. Hence, the PdZn/TiO_2−x NS electrocatalyst opens up new avenues towards energy conversion devices such as DAFCs and metal–air batteries. This new study provides an opportunity for further research to rationally design more carbon free supported nanostructured intermetallics by using different transition metals for efficient electrochemical energy storage devices.

中文翻译：

---

负载在缺陷 TiO2 纳米片上的金属间 PdZn 纳米颗粒作为载体：用于 PEMFC 中氧还原和甘油氧化反应的双功能电催化剂

探索简单灵活的方法合成具有高催化活性的氧还原反应（ORR）催化剂，对于燃料电池的大规模应用具有重要意义。在这里，我们通过涉及低温退火的浸渍工艺大规模生产的简单策略，在 TiO _{2- x} NS 载体催化剂上开发了金属间化合物 PdZn 。这种通过简单一步制备的电催化剂在室温下在酸性和碱性溶液中均表现出更好的 ORR 活性，具有更高的电化学活性表面积 (ECSA)。在 80°C 下重复方波电位循环测试超过 10000 次循环证实了催化剂的耐久性。使用 PdZn/TiO _{2- x的燃料电池}NS 催化剂显示出 855 mW cm ^-2的高功率密度，超过了 PdZn 负载的碳催化剂。此外，所提出的催化剂在质子交换膜燃料电池（PEMFC）性能中表现出超过100小时的出色稳定性。因此，所提出的 TiO _{2- x} NS 将成为未来 PEMFC 技术中碳载体的替代品。此外，与 PdZn/C 相比，PdZn/TiO _{2- x} NSs 对甘油氧化反应 (GOR) 的活性和稳定性以及对甘油酸生产的选择性也更高。因此，PdZn/TiO _{2- x}NS 电催化剂为 DAFC 和金属-空气电池等能量转换装置开辟了新途径。这项新研究为进一步研究提供了一个机会，通过使用不同的过渡金属来合理设计更多的无碳负载纳米结构金属间化合物，以实现高效的电化学储能装置。