Electrochemical Promotion of NO Reduction by C2H4 in Excess O2 Using a Monolithic Electropromoted Reactor and Pt–Rh Sputtered Electrodes

Abstract

The reduction of NO by ethylene in the presence of excess oxygen was investigated in a recently developed monolithic electropromoted reactor (MEPR). In this novel dismantlable monolithic-type electrochemically promoted catalytic reactor, thin (*40 nm) porous catalyst films are sputter-deposited on thin (0.25 mm) parallel solid electrolyte plates supported in the grooves of a ceramic monolithic holder and serve as electropromoted catalyst elements. Using Pt-Rh(1:1)/YSZ/Au-type catalyst elements, the 8-plate reactor operated with apparent Faradaic efficiency exceeding unity achieving significant and reversible enhancement in the rates of C 2 H 4 and NO consumption in presence of up to 10% O 2 in the feed at gas flow rates of 1,000 cc/min. The reactor, which is a hybrid between a monolithic catalytic reactor and a flat-plate solid oxide fuel cell, permits easy practical utilization of the electrochemical promotion of catalysis.

Theoretical insight into the origin of the electrochemical promotion of ethylene oxidation on ruthenium oxide

“…Herein, we rely on the model reaction of ethylene oxidation 31,32,[34][35][36][47][48][49][50] to demonstrate, using ab-initio computations, the effect of electrochemical potential on the surface reactivity. We will elucidate on the one hand the impact of the electrochemical potential on the surface state compared to thermal catalysis and on the other hand, the impact of the potential generated electric field on the reactivity of ethylene and oxygen activation.…”

Recent developments and trends in the electrochemical promotion of catalysis (EPOC)

“…Many studies have already been published [86][87][88][89][90] after the first report of MEPR [86] showing its advantages for several reaction (oxidations, reductions, hydrogenations etc.). In a very recent report [89] the reaction of NO by [89] is 0.08% and lamda value k (expresses the O 2 /fuel ratio present in automotive exhaust) is 1.12.…”

Electrochemical promotion of NO reduction by C2H4 in 10% O2 using a monolithic electropromoted reactor with Rh/YSZ/Pt elements

“…These studies have utilized YSZ [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39], b 00 -Al 2 O 3 [40][41][42][43][44][45][46][47][48][49], Nasicon [50], and proton conductor [51] solid electrolytes and, with very few recent exceptions [34][35][36][37][38], thick (0.5-1 lm) porous metal films. With a very recent exception utilizing Pt-Rh alloy catalysts [38], they were also limited to p O 2 values below 2% where the O 2 poisoning problem is not pronounced. The large majority of these studies were also limited to single-pellet reactors and only recently a monolithic electropromoted reactor (MEPR) was utilized for laboratory studies [34][35][36][37][38] and also tested under real car exhaust conditions [37] with moderate success and under relatively high fuel injection in the exhaust.…”

“…With a very recent exception utilizing Pt-Rh alloy catalysts [38], they were also limited to p O 2 values below 2% where the O 2 poisoning problem is not pronounced. The large majority of these studies were also limited to single-pellet reactors and only recently a monolithic electropromoted reactor (MEPR) was utilized for laboratory studies [34][35][36][37][38] and also tested under real car exhaust conditions [37] with moderate success and under relatively high fuel injection in the exhaust.…”