Production of COx-Free Hydrogen and Few-Layer Graphene Nanoplatelets by Catalytic Decomposition of Methane over Ni-Lignin-Derived Nanoparticles

Abstract

Nickel (Ni)-lignin nanocomposites were synthesized from nickel nitrate and kraft lignin then catalytically graphitized to few-layer graphene-encapsulated nickel nanoparticles (Ni@G). Ni@G nanoparticles were used for catalytic decomposition of methane (CDM) to produce COx-free hydrogen and graphene nanoplatelets. Ni@G showed high catalytic activity for methane decomposition at temperatures of 800 to 900 °C and exhibited long-term stability of 600 min time-on-stream (TOS) without apparent deactivation. The catalytic stability may be attributed to the nickel dispersion in the Ni@G sample. During the CDM reaction process, graphene shells over Ni@G nanoparticles were cracked and peeled off the nickel cores at high temperature. Both the exposed nickel nanoparticles and the cracked graphene shells may participate the CDM reaction, making Ni@G samples highly active for CDM reaction. The vacancy defects and edges in the cracked graphene shells serve as the active sites for methane decomposition. The edges are continuously regenerated by methane molecules through CDM reaction.

Recent Breakthroughs and Future Potential of Inorganic Nanocomposites in Hydrogen Generation

“…However, when exposed to the Ni core, the deposited graphene cells over Ni@G NPs act as active sites for the continuous decomposition of CH 4 . [51] The dark co-fermentation of glucose (C 6 H 12 O 6 ) and surplus algal biomass by Fe 3 O 4 NPs leads to higher H 2 production rates. The work of Srivastav and coworkers described that rate of H 2 synthesis increases 37% higher while using 7.5 mg/L of Fe 3 O 4 NPs.…”

“…The synthesized NCs were significantly used for the catalytic decomposition of CH 4 at 800–900 °C to yield H 2 and graphene nanoplates. However, when exposed to the Ni core, the deposited graphene cells over Ni@G NPs act as active sites for the continuous decomposition of CH 4 [51] …”

Nickel Nanoparticles Anchored on Bentonite Clay for Methane Decomposition with Ordered Carbon as a Product

“…25,26 However, studies employing metallic catalysts supported on non-oxides, such as commercial carbonaceous materials (carbon nanotubes (CNTs), activated carbon and carbon black) or obtained from renewable natural sources such as lignocellulosic biomass, are reported in the literature. [27][28][29] Esmizadeh et al 30 reported that catalysts with 25% Fe/ montmorillonite were used for the growth of carbon nanotubes through the deposition of chemical methane vapor. This study shows that the type of organo-modification of the clay before the insertion of Fe affected the purity, diameter, length and yield of the carbon nanotubes formed.…”

Room-Temperature NO2 Gas Sensors Based on Granulated Carbon Nanofiber Material

“…This material can be used for the synthesis of refractory compounds [33][34][35], as a filler for conductive epoxy composites [36], such as electrode for supercapacitors [37], and catalyst for the selective oxidation of H 2 S to sulfur [32,38] etc. Since the synthesis method of CNFs is an attractive CO x -free process [29,39,40] that may be applied to produce both hydrogen and carbon nanomaterials, the important task is to find the application of latter. One of the novel applications of the granulated CNF material for gas sensors was not yet investigated.…”