Ni-Based Catalyst Derived from NiAl Layered Double Hydroxide for Vapor Phase Catalytic Exchange between Hydrogen and Water

Abstract

A high-efficient and low-cost catalyst on hydrogen isotope separation between hydrogen and water is an essential factor in industrial application for heavy water production and water detritiation. In past studies, Pt-based catalysts were developed but not practical for commercial use due to their high cost for vapor phase catalytic exchange (VPCE), while for impregnated nickel catalysts with a lower cost the problems of agglomeration and low Ni utilization existed. Therefore, to solve these problems, in-situ grown Ni-based catalysts (NiAl-LDO) derived from a layered double hydroxide (LDH) precursor were fabricated and first applied in VPCE in this work. Compared with traditional impregnated Ni-based catalysts, NiAl-LDO catalysts own a unique layered structure, homogeneous dispersed metallic phase, higher specific surface area as well as stronger metal-support interactions to prevent active metal from agglomerating. These advantages are beneficial for exposing more active sites to improve dynamic contacts between H2 and HDO in a catalyst surface and can bring excellent catalytic activity under a reaction temperature of lower than 400 °C. Additionally, we found that the dissociative chemisorption of HDO and H2 occurs not only in Ni (111) but also in NiO species where chemisorbed H(ads), D(ads), OH(ads) and OD(ads) are formed. The results highlight that both of the Ni2+ species and Ni0 species possess catalytic activities for VPCE process.

Structural Stability of Ni/Al Layered Double Hydroxide Supported on Graphite and Biochar Toward Adorption of Congo Red

“…Based on the XRD pattern in Figure 2 (Hu et al, 2019b). Ni/Al LDH is then modi ed to form a composite using biochar and graphite which aims to obtain a material with greater adsorption capacity.…”

“…Adsorption is one of the most important methods to remove pollutants in e uents because of its high e ciency, easy operation, low cost and without secondary pollution. Since the adsorbent has the greatest in uence on the adsorption method, it is important to select the appropriate adsorbent for the adsorption in aqueous solution (Hu et al, 2019b). The properties of adsorbent in adsorption process is the most important factor to obtain high adsorption capacity.…”

Improved Water–Gas Shift Performance of Au/NiAl LDHs Nanostructured Catalysts via CeO2 Addition

“…The main Ni2p 3/2 peak of the bare NiAl is characterized by the binding energy (BE) of 855.4 eV and the shake-up peak, 6 eV apart from the main Ni 2p 3/2 peak, corresponding to the Ni 2+ state. Bearing in mind the nature of NiAl LDH, namely, the layered NiAl hydroxide sheet structure, the BE value is attributed to Ni(OH) 2 (855.3–856.6 eV) [ 77 , 78 , 79 , 80 ].…”

Recent Advances in Layered-Double-Hydroxides Based Noble Metal Nanoparticles Efficient Electrocatalysts

“…LDHs are a class of typical anionic layered materials with a structure similar to that of magnesium hydroxide (Figure 2). The chemical formula is usually [M 2+ 1−XM 3+ X (OH)2] x+ (A n− )x/n•mH2O, where M 2+ and M 3+ are metal cations located in the main plate layer, An-is the interlaminar anion, and m is the number of interlaminar crystal water in LDHs [46,47]. Structurally, each bivalent cation is surrounded by six hydroxyl octahedra; sharing edges; and forms an infinite sheet metal layer [48,49].…”