Minimization of Pt-electrocatalyst deactivation in CO2 reduction using a polymer electrolyte cell
Minimization of Pt-electrocatalyst deactivation in CO2 reduction using a polymer electrolyte cell
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DOI：
10.1039/d0re00083c
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发表时间：
2020-06-01
影响因子：
3.9
通讯作者：
Umeda, Minoru
中科院分区：
文献类型：
--
作者：
Matsuda, Shofu;Tamura, Shigehisa;Umeda, Minoru
最近报道了在理论Pt电极电势下，稀释CO2进料有效地产生CH 4，然而，该反应容易失活。为了解决这个问题，我们研究了CO2电还原生成CH 4的反应/失活机理。使用含有Pt/C催化剂的聚合物电解质单电池，通过简单地控制CO2进料浓度，CO2被还原为CH 4而没有过电位。如果在Pt-催化剂表面上形成的Pt-CO/Pt-H比为1：11或更高，则进行CH 4合成。CH 4生成反应的失活还取决于Pt-CO/Pt-H比（该比不满足1 ∶ 11或更高）。产甲烷的最佳Pt-CO/Pt-H比为1：18。此外，我们通过将阴极上的失活Pt表面扫到0.3 V，其中CO2/Pt-CO氧化还原反应同时发生，实现了86%的CH 4活性恢复。因此，我们建立了一个有效的低能耗的再活化反应，我们定义为一个中毒消除方法。总之，这项工作表明，聚合物电解质电池的应用与低浓度的CO2一起有效地减少Pt-电催化剂失活。
Diluted CO2 feeding was recently reported to efficiently generate CH4 at the theoretical Pt electrode potential, however, the reaction was easily deactivated. To solve this problem, we investigated the reaction/deactivation mechanism to produce CH4 from CO2 electroreduction. Using a polymer electrolyte single cell containing a Pt/C catalyst, CO2 was reduced to CH4 without overpotential by simply controlling the CO2 feed concentration. The CH4 synthesis proceeded if the Pt-CO/Pt-H ratio formed on the Pt-catalyst surface was 1 : 11 or higher. The deactivation of the CH4 generating reaction also depends on the Pt-CO/Pt-H ratio (the ratio does not satisfy 1 : 11 or higher). The optimum Pt-CO/Pt-H ratio to produce CH4 was 1 : 18. Furthermore, we achieved 86% recovery of CH4 activity by sweeping the deactivated Pt surface on the cathode up to 0.3 V where the CO2/Pt-CO redox reaction occurred simultaneously. As a result, an efficient less energy-intensive reactivation reaction that we defined as a poisoning-elimination method was established. Overall, this work demonstrated that the application of a polymer electrolyte cell together with a low concentration of CO2 is effective to minimize Pt-electrocatalyst deactivation.