Anion exchange membranes (AEMs) have been studied to improve conductivity for their high performance. The functional groups with positive charge could construct ion channels, which is the significant factor in determining the anions conductivity through the membrane. This report demonstrates the use of a new 2D nanomaterial as filler used in the quaterized polysulfone (QPSU) matrix for composite membrane performance enhancement of alkaline anion exchange membrane fuel cells (AAEMFCs). Ti 3 C 2 T x is functionalized with quaternary ammonium groups successfully etched by NH 4 HF 2 . The two kinds Ti 3 C 2 T x are synthesized and incorporated into QPSU based membranes by using a solution blending method. The QPSU/NH 4 HF 2 -Ti 3 C 2 T x composite membrane exhibits the hydroxide ionic conductivity nearly 2 times higher than that both of pristine QPSU and QPSU/LiF-Ti 3 C 2 T x membranes among 20–60 °C, and leads to substantial increase in peak power density of AAEMFCs by ~ 30% at 60 °C. The results indicate NH 4 + groups on the MXene surface further enhance the OH - conductivity. Furthermore, the QPSU membranes addition with two kinds Ti 3 C 2 T x both exhibit good mechanical property and thermal stability, and hold promise for application in AAEMFCs.
Xiaozhong Zheng,Shuxin Zhang,Xinying Zheng,Zhongbin Zhuang,Mingxia Gao,Yongfeng Liu,Hongge Pan,Wenping Sun
Ruthenium (Ru) is a more cost-effective alternative to platinum anode catalysts for alkaline anion-exchange membrane fuel cells (AEMFCs), but suffers from severe competitive adsorption of hydrogen (H ad ) and hydroxyl (OH ad ). To address this concern, a strongly coupled multisite electrocatalyst with highly active cluster-scale ruthenium-tungsten oxide (Ru-WO x ) interface, which could eliminate the competitive adsorption phenomenon and achieve high coverage of OH ad and H ad at Ru and WO x domains, respectively, is designed. The experimental and theoretical results demonstrate that WO x domain functions as a proton sponge to perpetually accommodate the activated hydrogen species that spillover from the adjacent Ru domain, and the resulting WO-H ad species are readily coupled with Ru-OH ad at the heterointerface to finish the hydrogen oxidation reaction with faster kinetics via the thermodynamically favorable Tafel-Volmer mechanism. The AEMFC delivers a high peak power density of 1.36 W cm −2 with a low anode catalyst loading of 0.05 mg Ru cm −2 and outstanding durability (negligible voltage decay over 80-h operation at 500 mA cm −2 ). This work offers completely new insights into understanding the alkaline HOR mechanism and designing advanced anode catalysts for AEMFCs.
Yi Liu,Lianrui Cheng,Shuqing Zhou,Chenggong Niu,Tayirjan Taylor Isimjan,Xiulin Yang
Exploiting a cost-effective electrocatalyst for hydrogen oxidation reaction (HOR) with high-performance and CO poisoning resistance is essential for the widespread application of alkaline anion exchange membrane fuel cells (AEMFCs). Herein, we craft a unique Ru-RuP 2 heterostructure within hollow mesoporous carbon sphere (Ru-RuP 2 @C) using phosphide-controlled phase-transition approach. Benefiting from the interfacial electron transfer from RuP 2 to Ru, the Ru-RuP 2 @C electrocatalyst exhibits impressive HOR performance with a mass activity of 2.87 mA μ g Ru − 1 . Notably, Ru-RuP 2 @C demonstrates strong tolerance to 1000 ppm CO, a capability lacking in PtRu/C and Pt/C. When serves as an anode catalyst for AEMFC, it achieves a peak power density of 521 mW cm −2 , comparable to Pt/C. Experimental and theoretical analyses reveal that the built-in electric field, resulting from work function differences, creates an asymmetric charge distribution that modulates the d -band center of Ru-RuP 2 @C. This optimizes the adsorption strength of hydrogen and hydroxide intermediates, thereby accelerating HOR catalytic kinetics.
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