Reduction of Crotonic Acid with Hydrogen on a Slurry Electrode
Reduction of Crotonic Acid with Hydrogen on a Slurry Electrode
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在浆料电极上用氢气还原巴豆酸
DOI：
10.1149/1.2403257
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发表时间：
1973
影响因子：
3.9
通讯作者：
H. Hulburt
中科院分区：
文献类型：
--
作者：
D. N. Baria;H. Hulburt
研究了一种由金属悬浮液或支撑金属粉末在与金箔电极接触的电解质中组成的浆液电极系统，作为氢电极用于在对甲苯磺酸钠支撑电解质中还原克罗东酸。研究了电流-电压曲线和电流效率。研究了悬浮液浓度、巴豆酸浓度、丁酸浓度、pH和温度对铂黑和钯碳浆的影响。结果表明，决定电位的反应是吸附在催化剂上的氢原子的放电。烯烃竞争吸附的氢，这改变了观察到的电位。在烯烃存在的情况下，观察到极低的阳极极限电流，这表明烯烃被强烈地吸附在阳极氢电极上。建立了阴极电流下的电动力学表达式：(i) 5% Pd在C log~上的电动力学表达式：日志k ~ -0.42日志CH + 0.49——0.013日志CR日志crh - T - 0.23日志Wcat EF 0.22 w / RT和(2)为泰党的黑色日志我——对数k - l - 0.52 CH + - ~ 0.077日志CR-t“0.028日志日志Wcat CRH2 ~ -0.45——0.30 EF /我是当前RT, k是一个常数,CH +氢离子浓度,CR是巴豆酸浓度,CRH2丁酸浓度,Wcat催化剂浓度,E是电极电位,F是法拉第常数,R是通用气体常数,和T是绝对温度。浆液电极系统包括与惰性集电极接触的电解质中的金属或支撑的金属粉末催化剂的悬浮液。它比普通的板型电极或由相同材料制成的多孔电极具有更大的表面积，可以在其上进行电极反应。Muller和Schwabe（1,2）首先测量了悬浮在电解质中的金属粉末的电位。后来Sokorskii和Druz（3,4）证明了将悬浮在电解质中的粉末金属催化剂的电位转移到固定电极上是可能的。Boutry， Bloch和Balaceau(5)表明，催化剂粉末悬浮在导电集电极存在的电解质中，具有经典紧凑电极的所有特性和用途。Gerischer和Held（6,7）表明，当氢被氧化或氧被还原时，从催化剂悬浮液中获得相当高的电流是可能的。他们用示波器跟踪单个催化剂颗粒的电流传输。Schwabe和Satsko(8)发现，镀铂碳悬浮液产生的电流与催化剂浓度无关，而用Raney镍和铂黑获得的电流明显更大，且与催化剂浓度成正比。
A slurry electrode system consisting of a suspension of metal or a supported metal powder in an electrolyte in contact with a gold foil electrode was studied as a hydrogen electrode for the reduction of crotonic acid in a supporting electrolyte of sodium p-toluene sulfonate. Current-voltage curves and current efficiency were studied. Effects of suspension concentration, crotonic acid concentration, butyric acid concentration, pH, and temperature were studied for platinum black and palladium-on carbon slurries. The results are consistent with the view that the potential-determining reaction is the discharge of hydrogen atoms adsorbed on the catalyst. Olefin competes for adsorbed hydrogen and this modifies the observed potential. Very low anodic limiting currents were observed in the presence of olefin, suggesting that it is strongly adsorbed on the anodic hydrogen electrode. The following electrokinetic expressions were established for cathodic currents:(i) for 5% Pd on C log~: log k~-0.42 log CH+--0.013 log CR--0.49 log CRHs-t-0.23 log Wcat w 0.22 EF/RT and (ii) for Pt black log i----log k-l-0.52 log CH+-~ 0.077 log CR-t" 0.028 log CRH2~-0.45 log Wcat--0.30 EF/RT where i is the current, k is a constant, CH+ is hydrogen ion concentration, CR is crotonic acid concentration, CRH2 is butyric acid concentration, Wcat is catalyst concentration, E is the electrode potential, F is Faraday's constant, R is universal gas constant, and T is the absolute temperature.A slurry electrode system consists of a suspension of a metal or a supported metal powder catalyst in an electrolyte in contact with an inert collector electrode. It has a larger surface area on which the electrode reaction can take place than plain plate-type electrodes or porous electrodes made of the same material. Muller and Schwabe (1, 2) first measured the potential of suspended metallic powders in an electrolyte. Later Sokorskii and Druz (3, 4) showed that it was possible to transfer the potential of a powdered metal catalyst suspended in an electrolyte onto a stationary electrode. Boutry, Bloch, and Balaceau (5) showed that a catalyst powder, suspended in an electrolyte in the presence of a conducting collector electrode, had all the properties and uses of a classical compact electrode. Gerischer and Held (6, 7) showed that it was possible to draw considerably higher currents from a suspension of catalyst when hydrogen was oxidized or oxygen reduced. They followed the transport of current by individual catalyst particles by means of an oscillograph. Schwabe and Satsko (8) found that the current drawn by a suspension of platinized carbon was independent of catalyst concentration, whereas the currents obtained with Raney nickel and platinum black were appreciably greater and proportional to the catalyst concentration.