The Key Laboratory of Fuel Cell Technology of Guangdong Province & The Key Laboratory of New Energy Technology of Guangdong Universities, School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510641, People's Republic of China.
ACS Appl Mater Interfaces. 2018 Jan 31;10(4):3530-3537. doi: 10.1021/acsami.7b15159. Epub 2018 Jan 18.
The severe dissolution of the cathode catalyst, caused by an undesired oxygen reduction reaction at the anode during startup and shutdown, is a fatal challenge to practical applications of polymer electrolyte membrane fuel cells. To address this important issue, according to the distinct structure-sensitivity between the σ-type bond in H and the π-type bond in O, we design a HD-Pt/TiN material by highly dispersing Pt on the TiN surface to inhibit the unwanted oxygen reduction reaction. The highly dispersed Pt/TiN catalyst exhibits excellent selectivity toward hydrogen oxidation and oxygen reduction reactions. With a Pt loading of 0.88 wt %, our catalyst shows excellent hydrogen oxidation reaction activity, close to that of commercial 20 wt % Pt/C catalyst, and much lower oxygen reduction reaction activity than the commercial 20 wt % Pt/C catalyst. The lack of well-ordered Pt facets is responsible for the excellent selectivity of the HD-Pt/TiN materials toward hydrogen oxidation and oxygen reduction reactions. Our work provides a new and cost-effective solution to design selective catalysts toward hydrogen oxidation and oxygen reduction reactions, making the strategy of using oxygen-tolerant anode catalyst to improve the stability of polymer electrolyte membrane fuel cells during startup and shutdown more affordable and practical.
在聚合物电解质膜燃料电池的启动和关闭过程中，阳极的氧还原反应导致阴极催化剂严重溶解，这对其实际应用是一个致命的挑战。为了解决这个重要问题，根据 H 原子中的 σ 键和 O 原子中的 π 键之间的明显结构敏感性，我们通过在 TiN 表面高度分散 Pt 设计了 HD-Pt/TiN 材料，以抑制不需要的氧还原反应。高度分散的 Pt/TiN 催化剂对氢气氧化和氧还原反应表现出优异的选择性。在 Pt 负载量为 0.88wt%时，我们的催化剂表现出优异的氢气氧化反应活性，接近商业 20wt%Pt/C 催化剂，而氧还原反应活性远低于商业 20wt%Pt/C 催化剂。有序 Pt 面的缺乏是 HD-Pt/TiN 材料对氢气氧化和氧还原反应具有优异选择性的原因。我们的工作为设计对氢气氧化和氧还原反应具有选择性的催化剂提供了一种新的、具有成本效益的解决方案，使得使用耐氧阳极催化剂来提高聚合物电解质膜燃料电池在启动和关闭过程中的稳定性的策略更加经济实惠和实用。
