Efficient purification of hydrogen cyanide by synergistic effects of electrochemical and liquid phase catalysis

• Published in: Ecotoxicology and environmental safety 2021-12, Vol.225, p.112784-112784, Article 112784
• Main Authors: Li, Zhishuncheng, Chen, Bangjin, Li, Junyan, Qu, Guangfei, Ning, Ping, Ma, Xi, Xie, Ruosong
• Format: Article
• Language: English
• Subjects: Efficient purification of HCN; Electrohydraulic synergy mechanism; Liquid phase catalytic oxidation
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2021.112784

In this study, Co, Cu, Pd, and Pd/Cu composite metal ions were used to synthesize metal nanoparticles with high efficiency in purifying hydrogen cyanide gas. The pure liquid phase catalytic purification of hydrogen cyanide gas was studied. According to the removal rate, the Pd/Cu composite metal ions had the best purification efficiency among the nanoparticles of different metal types. The removal rate order was Pd/Cu>Pd>Cu>Co. The gas after reaction were analyzed by gas chromatography, and it was found that HCN was converted into CO2, N2 and NH3 by nanoparticles. Then, Pd/Cu composite metal ions with the highest purification efficiency were used to study the electrochemical synergistic liquid-phase catalytic purification of HCN gas. The effects of electrochemical conditions and current on the electro-hydraulic synergistic purification were studied. The removal efficiency of HCN by electrochemical synergistic liquid phase catalysis was better than that by pure liquid phase catalysis. The different nanoparticles before and after HCN absorption were characterized and analyzed to explore the purification process of HCN. The purification mechanism of hydrogen cyanide by Pd-Cu catalyst under applied voltage was studied under certain conditions. During the catalytic reaction, the nano-catalyst was partially dissolved in liquid phase and partially HCN reacts with metal ions on the free or nanoparticles to form complex [Mc(CN)n]2−n. Homogeneous and quasi-homogeneous reactions in liquid phase interweave together to form a more complex reaction system. [Display omitted] •Successfully prepared high performance magnetic nanoparticles are used to purify HCN gas.•The removal rate for HCN gas is more than 65% in nearly 500 min.•HCN is converted into CO2, N2 and NH3 under the catalysis of nanoparticles.•Electrodialysis combined with liquid phase catalysis is more effective in purifying HCN•A more complex system is formed during the reaction.