China 
Africa 
Explore chapters and articles related to this topic
Biopolymers as Supports for Heterogeneous Catalysis: Focus on Chitosan, a Promising Aminopolysaccharide
Published in Arup K. SenGupta, Ion Exchange and Solvent Extraction, 2007
Eric Guibal, Thierry Vincent, Francisco Peirano Blondet
The reduction of palladium can be performed using different processes, alone or in combination: (a) sodium borohydride, (b) sodium formate, and (c) hydrogen gas (generated in situ by reaction of sulfuric acid with zinc powder). Several parameters can be used for the optimization of the process such as the weight loss (especially in processes involving the use of strongly acidic solutions) and the catalytic activity of Pd crystals. For the optimization of a synthesis procedure, Vincent and Guibal investigated the reduction of chromate using sodium formate as the hydrogen donor.344 This simple reaction has no practical interest except for the ready analysis and testing of catalytic activity. Best results are obtained when using glutaraldehyde cross-linking agent; sulfate-treated support may not be sufficiently stable (especially when reduction is operated in sulfuric acid solutions, for H2in situ generation). Despite higher sorption capacities, the catalytic materials prepared with sulfate-treated support are less active than glutaraldehyde-treated materials. The most appropriate reduction process combines in this case the treatment with sodium borohydride, followed by reduction with in situ generated H2. However, palladium reduction is not complete as evidenced by XPS analysis: about 40 to 50% of Pd remains in the Pd(II) original form. The catalytic activity of chitosan-supported Pd is significantly higher than that of palladium microparticles prepared by reduction and precipitation.
Atomic Absorption Spectroscopy
Published in James P. Lodge, Methods of Air Sampling and Analysis, 2017
Hydride AA applications involve the generation of a volatile hydride of the analyte by means of a reducing agent added to a reaction vessel containing an acidic solution of the sample. The liberated hydride is transported to a heated quartz cell atomizer by an inert carrier gas. Sodium borohydride is most commonly used as the reducing agent. Since the hydride is separated from the matrix, advantages include high sensitivity and reduced interferences. However, this technique is only applicable to a limited number of elements. Those elements that form volatile hydrides include As, Se, Bi, Sb, and Te.
Nanotechnology for Energy and the Environment
Published in Shilpi Birla, Neha Singh, Neeraj Kumar Shukla, Nanotechnology, 2022
Nanotubes can be used for generation of electricity for building thermocells while cells act at different temperatures. They could be wrapped around hot pipes to get electricity from heat, which is wasted in normal conditions. Hydrogen can be stored for fuel cell powered cars. Hydrogen can be bonded to graphene for an increase in energy that results in more storage of hydrogen and lightweight fuel tanks. The nanoparticles sodium borohydride have shown effective storage of hydrogen. [16-18]
Modelling and optimisation of hardness in citrate stabilised electroless nickel boron (ENi-B) coatings using back propagation neural network – Box Behnken design and simulated annealing – genetic algorithm
Published in Transactions of the IMF, 2021
M. Vijayanand, R. Varahamoorthi, P. Kumaradhas, S. Sivamani
An electroless nickel bath is composed of the nickel ion source, complexing agent, reducing agent and stabiliser. Nickel chloride or sulphate is used as the source for metal deposition. Complexing agents stabilise the solution by preventing the excess free metal ion concentration and also act as a pH buffer. The function of the reducing agent is to reduce the metal ions by providing electrons. Nickel ion reduction using hypophosphite gives nickel-phosphorus alloys, and that reduced using dimethylamine borane (DMAB) or sodium borohydride provides nickel-boron alloys. Sodium borohydride has higher reduction efficiency among the discussed reducing agents.7 Stabilisers prevent the breakdown (decomposition) of a solution by masking the active nuclei.8,9
Catalytic activity of cobalt-boron-fluoride particles with different solvent mediums on sodium borohydride hydrolysis for hydrogen generation
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Mehmet Sait Izgi, Ömer Şahin, Orhan Baytar, Cafer Saka
Hydrogen is an efficient energy carrier. The borohydride compounds are contemplated for low temperature fuel cell applications as potential liquid-phase hydrogen carriers, and some of them have been investigated for hydrolysis studies by hydrogen hydrolysis. The borohydride compounds with super hydrogen capacities are among the potential materials for the storage of hydrogen. Among metal hydrides, SB has some advantages such as high hydrogen storage capacity of 10.8%, high stability and non-flammability at high pH, optimum control over the hydrogen production rate, ease of use and availability (Eberle, Felderhoff, and Schüth 2009; Wang et al. 2015).