Biotemplate-Assisted Synthesis of Layered Double Oxides Confining Ultrafine Ni Nanoparticles as a Stable Catalyst for Phenol Hydrogenation

Abstract

A confined Ni(0) nanocatalyst derived from NiAl-layered double hydroxide (NiAl-LDH), with ultrafine Ni nanoparticles implanted in the Ni x Al y O support, was first fabricated by the urea coprecipitation method using pine pollen as a biotemplate, together with subsequent calcination/ reduction process. This hollow biotemplate-assisted catalyst displayed high phenol-hydrogenation activity and stability, which can be ascribed to its higher surface area, better dispersibility, and ultrafine Ni particle size. The hollow morphology and confinement effect of lamellar NiAl-LDH can not only lead to better dispersion of the active Ni(0) species, but also strengthen the interaction between Ni(0) species and Ni x Al y O support. This protocol can overcome the shortcomings of conventional LDH-derived catalysts that lack specifically shaped morphology and hierarchical structure, inhibiting the aggregation of the Ni nanoparticles, hence resulting in its good activity and stability.

Electrically Heatable Graphene Aerogels as Nanoparticle Supports in Adsorptive Desulfurization and High‐Pressure CO2 Capture

“…[30] The additional benefits of MMO-based sorbents include, non-reactive organosulfur binding (enabling sorbent regeneration via relatively mild temperature-or pressure-swing), good thermal and chemical stability, very good performance in the presence of common, competing adsorbate species (e.g., water), and high selectivity for challenging, sterically hindered organosulfurs. [28,31] In the context of gas-phase sorption applications, the adsorption of CO 2 onto porous solid sorbents is of major technological and environmental importance. LDH-derived MMO materials are particularly interesting sorbents for pre-combustion CO 2 capture and hydrogen generation via sorption-enhanced reaction (SER) processes.…”

“…[ 30 ] The additional benefits of MMO‐based sorbents include, non‐reactive organosulfur binding (enabling sorbent regeneration via relatively mild temperature‐ or pressure‐swing), good thermal and chemical stability, very good performance in the presence of common, competing adsorbate species (e.g., water), and high selectivity for challenging, sterically hindered organosulfurs. [ 28,31 ]…”

A Doubly Confined Nickel‐Based Catalyst Derived from Hydrotalcite‐Montmorillonite Composite: Preparation and Hydrogenation Performance

“…XRD patterns of the calcined Ni/MMT‐Al 2 O 3 , Ni/MMT and Ni‐AOM are shown in Figure 3b. It can be seen that Ni/MMT‐Al 2 O 3 and Ni/MMT both exhibit typical diffraction peaks of NiO at 2θ=37.1, 43.5, 62.1, and 75.3° [27] . These peaks are sharp, indicating that the particle sizes of NiO are large.…”

Synthesis of Nanocrystalline Mg-Al Hydrotalcites in the Presence of Starch—the Effect on Structure and Composition

“…The method is considered particularly attractive owing to the low cost, renewable nature, biodegradable character, and environmental compatibility of natural reagents. A literature search shows that synthesis of Ht with the use of sacrificial biotemplates is a very recent tendency, with research concentrating so far on the hard templating syntheses, in which the nanostructure of rigid biomaterials was replicated in the final Ht product [10][11][12][13][14][15][16][17][18][19]. In most works cellulosic polymers of various provenience have been used in the capacity of sacrificial biotemplates.…”

“…Zhang et al [12] demonstrated that advanced Zn-Al Ht/Al 2 O 3 composites with tunable compositions and micro/nanostructures could be grown by structure replication of cellulose fibers. In some cases complex biological nanoarchitectures, such as those provided by pine pollen or surface of legume, were used, and resulted in hierarchical nanostructures with improved photocatalytic and/or catalytic performance [10,17,19].…”