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

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1688 ◽  
Author(s):  
Xiaoyu Hu ◽  
Peilong Li ◽  
Xin Zhang ◽  
Bin Yu ◽  
Chao Lv ◽  
...  

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.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Panlong Zhai ◽  
Mingyue Xia ◽  
Yunzhen Wu ◽  
Guanghui Zhang ◽  
Junfeng Gao ◽  
...  

AbstractRational design of single atom catalyst is critical for efficient sustainable energy conversion. However, the atomic-level control of active sites is essential for electrocatalytic materials in alkaline electrolyte. Moreover, well-defined surface structures lead to in-depth understanding of catalytic mechanisms. Herein, we report a single-atomic-site ruthenium stabilized on defective nickel-iron layered double hydroxide nanosheets (Ru1/D-NiFe LDH). Under precise regulation of local coordination environments of catalytically active sites and the existence of the defects, Ru1/D-NiFe LDH delivers an ultralow overpotential of 18 mV at 10 mA cm−2 for hydrogen evolution reaction, surpassing the commercial Pt/C catalyst. Density functional theory calculations reveal that Ru1/D-NiFe LDH optimizes the adsorption energies of intermediates for hydrogen evolution reaction and promotes the O–O coupling at a Ru–O active site for oxygen evolution reaction. The Ru1/D-NiFe LDH as an ideal model reveals superior water splitting performance with potential for the development of promising water-alkali electrocatalysts.


CrystEngComm ◽  
2022 ◽  
Author(s):  
Meng Ya Yang ◽  
Rong Zhao ◽  
Yi Liu ◽  
Hua Lin

In this work, high efficient electrocatalyst Fe-Ni2P/N-GO with hierarchical structure was developed through phosphating NiFe-based layered double hydroxide (LDH) supported by N-doped graphene oxide (GO), which was assembled by the...


NANO ◽  
2020 ◽  
Vol 15 (02) ◽  
pp. 2050021
Author(s):  
Qi Tang ◽  
Menghan Ye ◽  
Li Ma ◽  
Tao Zhou ◽  
Mengyu Gan ◽  
...  

In this work, the Ni–Mn layered double hydroxide (Ni–Mn LDH) nanopetals are fabricated on three-dimensional reduced graphene oxide/Ni foam (RGO/NF) by one-step hydrothermal method, in which the suspension of graphene oxide (GO) is directly reduced by nickel foam (NF) to obtain NF/RGO. The composite, which consists of interconnected Ni–Mn LDH nanopetals, forms a macroporous structure. Such an open space can promote electrolyte dispersion and ion diffusion of active substances, thus enhancing capacitance performance. Remarkable, during crystal growth, RGO can not only provide active sites for Ni–Mn LDH nanopetals, but also effectively connect Ni–Mn LDH nanopetals to NF, further promoting the electrochemical behavior of composite material. Moreover, RGO possess reasonable chemical stability which can improve the mechanical properties of the composite to obtain good stability. The experimental results show that the NF/RGO electrode material with Ni–Mn LDH nanopetals has excellent specific capacitance of 2250[Formula: see text]F[Formula: see text]g[Formula: see text] at 1[Formula: see text]A[Formula: see text]g[Formula: see text], good rate performance (the capacitance retention rate is still 64.0% at 10[Formula: see text]A[Formula: see text]g[Formula: see text] and excellent cycle life (45.1% at 10[Formula: see text]A[Formula: see text]g[Formula: see text] after 5000 cycles). NR/NM–LDH is used as the positive electrode and activated carbon is used as the negative electrode to assemble the asymmetric supercapacitor, the proper power density and energy density indicates that the NR/NM–LDH composite has great potential as an electrode material for supercapacitors.


2019 ◽  
Vol 3 (5) ◽  
pp. 842-850 ◽  
Author(s):  
Jinxue Guo ◽  
Jikang Sun ◽  
Yanfang Sun ◽  
Qingyun Liu ◽  
Xiao Zhang

Ultrafine Pd nanoparticles with less than 0.12 at% are electrodeposited on nickel foam supported NiFe LDH to obtain improved intrinsic activity, more active sites, and enhanced charge transfer for improved bifunctionality towards overall water splitting.


2019 ◽  
Vol 136 (34) ◽  
pp. 47884 ◽  
Author(s):  
Cataldo Simari ◽  
Carmelo Lo Vecchio ◽  
Apostolos Enotiadis ◽  
Mariano Davoli ◽  
Vincenzo Baglio ◽  
...  

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