Ammonia Synthesis via Atmospheric Plasma Catalysis: Zeolite 5A, a Case of Study

Abstract

Herein, we demonstrate the synthesis of ammonia via atmospheric dielectric barrier discharge (DBD) plasma discharge over zeolite 5A. The presence of the zeolite in the DBD reactor promoted the formation of microdischarges and a change of the voltage−current characteristics of the reactor, leading to an enhanced catalytic performance. The perturbation of the zeolite surface electronic properties due to atmospheric plasma led to an enhanced reactive state at the zeolite surface which promoted the dissociation of nitrogen and the subsequent formation of ammonia. An energy yield of 15.5 g-NH 3 /kW h was observed at an equimolar N 2 to H 2 ratio in the presence of zeolite 5A, which is at least 50 times higher than that obtained in the absence of the zeolite.

Fundamental Properties and Applications of Dielectric Barrier Discharges in Plasma‐Catalytic Processes at Atmospheric Pressure

“…Moreover, the plasma process allows to surpass the equilibrium limitation of thermal catalysis at elevated temperatures by kinetically trapping ammonia [116]. A wide variety of different catalysts has been applied in plasma-assisted ammonia synthesis, ranging from the semimetal gallium [117] over diamond-like carbon structures [118] and zeolites [119] to traditional ammonia synthesis catalysts such as Ru, Fe and other metals supported on Al 2 O 3 or MgO [117,[120][121][122][123]. In Tab.…”

Plasma-driven catalysis: green ammonia synthesis with intermittent electricity

“…224,225 An afterglow normally describes the effluent of a plasma reactor. However, the term is sometimes used more broadly to indicate that ( plasma) species are no longer exposed to The listed plasma reactors are dielectric barrier discharge (DBD), 96,131,142,[143][144][145][146][147][148][149][150][151][152][153][154][155][156][157][158][159][160][161][162][163][164][165][166][167][168][169] (low pressure) glow discharge (GD), 170,171,[172][173][174][175][176][177][178][179]180 microwave plasma (MW), [181][182][183][184][185]…”

“…103,[273][274][275] Therefore, low pressure plasma reactors such as MW and RF plasmas require a near complete conversion at an energy yield of 100-200 g-NH 3 kW h −1 , because separation of ammonia is not feasible. The highest energy yield reported so far is Original references: DBD (AC), 144,[146][147][148][151][152][153]159,[164][165][166]169,276,277 DBD ( pulse), 158,165 Glow Discharge, 174 MW 186,278,279 and RF. 182,187,188,[190][191][192]194 In some cases, the reported units have been converted to g-NH 3 kW h −1 for the energy yield, and ppm for the ammonia concentration.…”

“…Akay et al 152,168 reported increased ammonia yield on introduction of dielectric materials in a physical mixture with supported Co and Ni catalysts, altering the plasma discharge characteristics. Original references: DBD (AC), 144,[146][147][148][151][152][153]159,[164][165][166]169,276,277 DBD ( pulse). 158,165 Other packings.…”

A Review about the Recent Advances in Selected NonThermal Plasma Assisted Solid–Gas Phase Chemical Processes

“…Shah et al [31] investigated the use of zeolite 5A in the ammonia plasma-assisted synthesis. The formation of microdischarges and a change of the voltage−current characteristics of the reactor was promoted by the presence of the zeolite.…”