Carbon Nanotubes Deposited on Mordenite Zeolite/NiAl-Layered Double Hydroxide Composites as Electrocatalysts for 2,5-Furandicarboxylic Acid Production from 5-Hydroxymethylfurfural

Abstract

The nanostructured free-standing NiAl-MOR-CNTs electrocatalysts containing carbon nanotubes (CNTs) deposited on mordenite (MOR) zeolite/NiAl-layered double hydroxide (NiAl-LDH) have been successfully fabricated. Initially, the core-shell NiAl-LDH-MOR with hierarchical structures was observed via an aqueous miscible organic solvent treatment process to deposit nanosized NiAl-LDH homogeneously on a zeolite surface. The synthesized NiAl-LDH-MOR composites were calcined to produce highly dispersed metal oxides catalyzing the CNTs formation via chemical vapor deposition using bioethanol as a feedstock, eventually producing the NiAl-MOR-CNTs composites. To illustrate the beneficial aspect of the prepared composite, they were mixed with Nafion as a binder and pressed into circular pellets used as free-standing electrodes for electrochemical oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), an important renewable monomer of bioplastic. The prepared free-standing electrodes exhibited an excellent catalytic performance of 100% conversion of HMF with a high selectivity of FDCA up to 92% under ambient conditions. Moreover, the synthesized electrocatalysts can be recycled even after several consecutive cycles without any loss of catalytic activity, confirming a high stability of the synthesized electrodes. This work illustrates the design of electrocatalysts by using conductive CNTs grown on highly dispersed metal active sites on zeolite/LDH composites without using commercial conductive supports such as nickel foam or carbon fiber paper.

Rational Design of Fe Single Sites Supported on Hierarchical Zeolites via Atomic Layer Deposition for Few-Walled Carbon Nanotube Production

“…These factors hinder the production of highly qualified CNTs. 49 In our previous work, 50 we demonstrated a promising approach by converting bioethanol to bioethylene through the ethanol dehydration process, using acidic hierarchical ZSM-5 as the catalyst; subsequently, ethylene can be further converted to CNTs. As reported previously, the acidity of Hie-ZSM-5, which serves as the active function of the catalyst for ethanol dehydration, 51 plays an essential role in achieving a high ethylene yield.…”

Perspectives on Recent Advances in Hierarchical Zeolites for Bioethanol Conversion to Chemicals, Jet Fuels, and Carbon Nanotubes

“…Unexpectedly, the utilization of metal-containing hierarchical zeolites as catalysts for CNTs synthesis represents a novel approach that has recently received limited attention. Tantisriyanurak and co-workers reported that homogeneous MWCNTs (41% yield) with an outer diameter of 27 ± 9.5 nm were successfully synthesized (Figure ). This synthesis was achieved using NiAl-LDH-MOR composites through a chemical vapor deposition process involving bioethylene produced from bioethanol.…”

“…(E) TEM image and (F) SEM image of 20%NiAl-MOR-CNTs. Reproduced from ref . Copyright 2023 American Chemical Society.…”

Unraveling the Electrocatalytic Activity in HMF Oxidation to FDCA by Fine‐Tuning the Degree of NiOOH Phase Over Ni Nanoparticles Supported on Graphene Oxide

“…[10] In addition, the Ni/NOOH electrode can also be applied as a working electrode under a flow system for continuously producing FDCA, eventually reaching the FDCA yield and FE of ≈ 90% and 80%, respectively. [6b] Additionally, altering an electronic property of Ni active metals by combining with other promoters making the Ni-containing composites, such as NiFe layered double hydroxide, [11] Ni 3 S 2 , [12] Ni 2 P, [13] Ni/NiO encapsulated in oxygen-doped graphene, [14] and NiAl-MOR-CNTs composites, [15] is one of the most promising strategies for enhancing the HMF electrooxidation to FDCA. In addition to altering an electronic property of Ni-based electrocatalysts, tailoring an electronic property of Ni metal by changing the valence state of Ni from the low Ni valence state of Ni metal (Ni 0 ) to the higher valence state of the NiOOH (Ni 3+ ) phase through Ni surface reconstruction without adding any promoters is an attractive approach for improving the efficiency of the Nibased electrocatalysts in HMF electrooxidation to FDCA.…”