Balancing Water Dissociation and Current Densities To Enable Sustainable Hydrogen Production with Bipolar Membranes in Microbial Electrolysis Cells
Balancing Water Dissociation and Current Densities To Enable Sustainable Hydrogen Production with Bipolar Membranes in Microbial Electrolysis Cells
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DOI：
10.1021/acs.est.9b05024
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发表时间：
2019-12-17
影响因子：
11.4
通讯作者：
Logan, Bruce E.
中科院分区：
文献类型：
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作者：
Wang, Xu;Rossi, Ruggero;Logan, Bruce E.
使用双室微生物电解池（MEC）的氢气生产通常受到阴极电解液pH的快速上升的不利影响，这是因为用于析氢反应的质子消耗。虽然使用双极膜（BPM）将保持更恒定的电解质pH值，但该膜上的大电压损失会降低性能。为了克服这些限制，我们使用酸性阴极电解液来补偿使用BPM所引起的潜在损失。使用Pt阴极和BPM获得1.2 +/- 0.7 L-H-2/L/d（j（max）= 10 +/- 0.4 A/m（2））的氢气产生速率，其中两个室之间具有pH差（Δ pH = 6.1）。该生产速率是具有阴离子交换膜的常规MEC（AEM，0.43 +/- 0.1 L-H-2/L/d，j（max）= 6.5 +/- 0.3 A/m（2））的生产速率的2.8倍。使用BPM和Pt/C，阴极电解液pH在9天内逐渐增加到11 +/-0.3，这降低了电流产生（j（max）= 2.5 +/-0.3A/m2）。然而，该性能比使用AEM获得的性能好得多，因为阴极电解液pH在仅仅一天后增加到10 +/-0.4。活性炭阴极与BPM的使用能够在12天的较长时间内实现稳定的性能，尽管其降低了氢气生产速率（0.45 +/- 0.1 L-H-2/L/d）。
Hydrogen production using two-chamber microbial electrolysis cells (MECs) is usually adversely impacted by a rapid rise in catholyte pH because of proton consumption for the hydrogen evolution reaction. While using a bipolar membrane (BPM) will maintain a more constant electrolyte pH, the large voltage loss across this membrane reduces performance. To overcome these limitations, we used an acidic catholyte to compensate for the potential loss incurred by using a BPM. A hydrogen production rate of 1.2 +/- 0.7 L-H-2/L/d (j(max) = 10 +/- 0.4 A/m(2)) was obtained using a Pt cathode and BPM with a pH difference (Delta pH = 6.1) between the two chambers. This production rate was 2.8 times greater than that of a conventional MEC with an anion exchange membrane (AEM, 0.43 +/- 0.1 L-H-2/L/d, j(max) = 6.5 +/- 0.3 A/m(2)). The catholyte pH gradually increased to 11 +/- 0.3 over 9 days using the BPM and Pt/C, which decreased current production (j(max) = 2.5 +/- 0.3 A/m(2)). However, this performance was much better than that obtained using an AEM as the catholyte pH increased to 10 +/- 0.4 after just one day. The use of an activated carbon cathode with the BPM enabled stable performance over a longer period of 12 days, although it reduced the hydrogen production rate (0.45 +/- 0.1 L-H-2/L/d).