Non-Thermal Ammonia Decomposition for Hydrogen Production over Carbon Films under Low-Temperature Plasma—In-Situ FTIR Studies

Abstract

Due to easy storage and transportation, liquid hydrogen carriers will play a significant role in diversifying the energy supply pathways by transporting hydrogen on a large scale. Thus, in this study, amorphous carbonaceous materials have been employed for hydrogen production via ammonia decomposition under non-thermal plasma (NTP) conditions. The adsorption and splitting of ammonia over carbons differing in the chemical structure of surface functional groups have been investigated by in situ spectral studies directly under NTP conditions. As a result of NH3 physical and chemical sorption, surface species in the form of ammonium salts, amide and imide structures decompose immediately after switching on the plasma environment, and new functionalities are formed. Carbon catalysts are very active for NH3 splitting. The determined selectivity to H2 is close to 100% on N-doped carbon material. The data obtained indicate that the tested materials possess excellent catalytic ability for economical, COx-free hydrogen production from NH3 at a low temperature.

Room-Temperature Oxygen Dissociative Chemisorption on Carbon Surface–Experimental Evidence

“…The IR spectral changes observed when exposing the carbon surface to the oxygen atmosphere at temperatures as high as 300 °C were described in our previous studies. 22,23,29 The infrared spectrum of the C des �the carbon sample outgassed at 600 °C (Figure 1a)�shows the presence of two main groups of signals sharp at ca. 1600 cm −1 and mutually overlapped in the range of 1100−1500 cm −1 .…”

Plasma Catalysis for Hydrogen Production: A Bright Future for Decarbonization

“…Moszczyńska et al also reported a plasma power dependence for NH 3 decomposition over carbonaceous catalyst material. The authors show increased NH 3 conversion from 40% to ∼100% when the normalized power was increased from 150 to 900 W/m . Gorky et al investigated the effect of NH 3 decomposition on MgTiO 3 metal-based perovskites under cold plasma conditions.…”

“…However, the temperature of the NTAP increased significantly by ∼200 K across the power range tested, which could have also influenced the reaction performance. 198 Moszczynśka et al 293 also reported a plasma power dependence for NH 3 decomposition over carbonaceous catalyst material. The authors show increased NH 3 conversion from 40% to ∼100% when the normalized power was increased from 150 to 900 W/m.…”

In situ FTIR study of 2D-carbon materials for CO2 splitting under non-thermal plasma environment – selective CO production

“…Carbon-assisted CO 2 conversion studies under NTP environment were carried out in a glow discharge reactor and in an IR-vacuum cell, as described previously 33,34 plugged into a vacuum line. The initial pressure of CO 2 was constant and equal to 0.38 torr.…”