二氧化钛改性炭黑催化剂电合成H2O2反应器设计与性能优化

Reactor design and performance optimization for electrosynthesis of H2O2 on titanium dioxide modified carbon black catalyst

中文关键词: 电合成  反应器设计  气体扩散电极  运行参数优化

英文关键词: electrosynthesis  reactor design  gas diffusion electrode  operating parameter optimization

中文摘要:

      通过二电子氧还原反应(2e-ORR)直接电合成过氧化氢(H2O2)为能源密集型蒽醌氧化工艺提供了一种可行的替代方案．然而，从实验规模转变到工业规模电合成H2O2的过程中，一个主要的障碍是开发大电极面积的反应器．因此，以二氧化钛改性炭黑为阴极催化剂，设计了81 cm2阴极的H池反应器和气体扩散反应器，并构建了电合成H2O2的反应系统．由于氧传质和产热无法有效排出，H池反应器难以在50 mA/cm2以上电流密度下高效率运行，相比之下，气体扩散反应器可以在100 mA/cm2下实现525.8 mmol/(L·h)的高H2O2产率，且法拉第效率达到84%．通过调节电流密度和阴极液流速等运行参数，该气体扩散反应器电合成H2O2的最低电解质和电能总成本为5.149元/kg．该工作为设计低成本的分散式H2O2生产系统提供了可行的策略．

英文摘要:

      The direct electrosynthesis of hydrogen peroxide (H2O2) via a two-electron oxygen reduction reaction (2e-ORR) offers a viable alternative to the energy-intensive anthraquinone oxidation process. However, transitioning from laboratory-scale to industrial-scale electrosynthesis of H2O2 poses a significant obstacle in developing reactors with large electrode areas. Therefore, an H-cell reactor and a gas diffusion reactor with 81 cm2 cathode are designed and a reaction system for electrosynthesis of H2O2 is constructed using titanium dioxide modified carbon black as cathode catalyst. Due to ineffective oxygen mass transfer and heat dissipation, the H-cell reactor struggles to operate efficiently at current densities exceeding 50 mA/cm2. In contrast, the gas diffusion reactor achieves a high H2O2 production rate of 525.8 mmol/(L·h) at 100 mA/cm2 with a Faradaic efficiency of 84%. By adjusting the operating parameters such as current density and catholyte flow rate, the lowest total cost of electrolyte and electrical energy for electrosynthesis of H2O2 in this gas diffusion reactor is 5.149 RMB/kg. This work provides a feasible strategy for designing a low-cost decentralized H2O2 production system.