Reaction Acceleration of Nanoporous High-Purity Pd Film Formation by Dealloying of Al-Pd-N Film in pH-Controlled EDTA Solution

MRS Advances ◽  
2020 ◽  
Vol 5 (11) ◽  
pp. 531-538
Author(s):  
Tomoya Nishi ◽  
Syuya Hasegawa ◽  
Takuji Ube ◽  
Takashi Ishiguro

AbstractMetallic palladium (Pd) is used for hydrogen storage and detection. Fabrication of a nanoporous (NP) Pd structure can increase the specific surface area leading to a significant improvement in the sensitivity. In our previous study, we succeeded in forming a NP-Pd film by dealloying an Al-Pd alloy film using citric acid as a chelating agent. This method was environmentally friendly but had a long reaction time and a considerable amount of Al remained after dealloying; hence, the Pd purity was reduced. In this study, we succeeded in forming a higher purity NP-Pd film faster by dealloying the nitrogen-containing Al-Pd (Al-Pd-N) film using ethylene-diamine-tetraacetic-acid (EDTA) as a chelating material.

2014 ◽  
Vol 900 ◽  
pp. 361-364
Author(s):  
Xiao Hui Wang ◽  
Xi Hua Du ◽  
Li Min Dong

Esters of Citric acid and palmityl alcohol were synthesized by esterification reaction under catalysis of cation exchange resin and P-toluene sulfonic acid respectively. The effects of amount of catalyst, ratio of raw materials, reaction time and temperature on the synthesis reaction were investigated . The experimental results showed that optimum of process conditions were 1:1~1:1.5 molar ratio of citric acid and palmityl alcohol, reaction temperature of 130~140°C, reaction time of 2 h. Conversion of palmityl alcohol were all more than 90% under 0.3% dosage using p-toluene sulfonic acid as the catalyst, or 0.5% dosage using 721 cation exchange resin with sulfonic acid type as catalyst. The synthesized product had good surface activity.


2014 ◽  
Vol 1081 ◽  
pp. 88-92
Author(s):  
Hui Liu ◽  
Jiu Lan Dai

Effect of organic matter and organic acid on the heavy metals, especially, chromium (Cr) release in the sediment was researched. Glucose and soluble organic starch was used as organic matter, as well, citric acid and ethylene diamine tetraacetic acid (EDTA) were simulated as organic acid. The results showed that best adsorption time of glucose on Cr was 5h, the optimal dosage was 0.1g g-1; best adsorption time of organic soluble starch was 4h, and the optimum adding amount of 0.08g/g; best adsorption time of citric acid was 5h, the best concentration 0.005mol g-1; optimal adsorption time of organic acid EDTA was 3h, the optimum adding amount of 0.12g g-1. Glucose, soluble starch and citric acid significantly effected on the release of Cr in the sediment, however, influence of EDTA on the release of Cr was not so evident.


Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 619 ◽  
Author(s):  
Xuqiang Zhao ◽  
Li Qin ◽  
Michael Gatheru Waigi ◽  
Pengfei Cheng ◽  
Bing Yang ◽  
...  

The availability of bound residues of polycyclic aromatic hydrocarbons (PAHs), in reference to their parent compounds, can be enhanced by microbial activity and chemical reactions, which pose severe risks for the ecosystems encompassing contaminated soils. Considerable attention has been raised on how to remove these bound residues from PAH-contaminated soils. This paper provides a novel application of Fenton oxidation in the removal of bound residues of model PAHs, such as naphthalene (NAP), acenaphthene (ACP), fluorene (FLU) and anthracene (ANT), from naturally contaminated soils. The citric acid-enhanced Fenton treatment resulted in the degradation of bound PAH residues that followed pseudo-first-order kinetics, with rate constants within 4.22 × 10−2, 1.25 × 10−1 and 2.72 × 10−1 h−1 for NAP, FLU, and ANT, respectively. The reactivity of bound PAH residues showed a correlation with their ionization potential (IP) values. Moreover, the degradation rate of bound PAH residues was significantly correlated with H2O2-Fe2+ ratio (m/m) and H2O2 concentrations. The highest removal efficiencies of bound PAH residues was up to 89.5% with the treatment of chelating agent oxalic acid, which was demonstrated to be superior to other acids, such as citric acid and hydrochloric acid. This study provides valuable insight into the feasibility of citric acid-Fenton and oxalic acid-Fenton treatments in rehabilitating bound PAH residues in contaminated soils.


2009 ◽  
Vol 1166 ◽  
Author(s):  
Keishi Nishio ◽  
Tomomi Okada ◽  
Naoto Kikuchi ◽  
Satoshi Mikusu ◽  
Tsutomu Iida ◽  
...  

AbstractDelafossite CuYO2 and Ca doped CuYO2 were prepared by thermal decomposition of a metal-citric acid complex. The starting solution consisted of Cu acetate, Y acetate and Ca acetate as the raw materials. Citric acid was used as the chelating agent, and acetic acid and distilled water were mixed as a solvent. The starting solutions were heated at 723 K for 5 h after drying at 353 K. The obtained powders were amorphous and single phase of orthorhombic Cu2Y2O5 was obtained by heat-treated the amorphous powder at a temperature range between 1073 and 1373 K for 3 h in air. Furthermore, Heat-treating the obtained orthorhombic Cu2Y2O5 at above 1373 K in air caused it to decompose into Y2O3, CuO and Cu2O. On the other hand, the sample powder prepared from a starting solution without citric acid, i.e., single phase of orthorhombic Cu2Y2O5 could not be obtained under the same synthesis conditions as that for a solution with citric acid. We were able to obtain delafossite CuYO2 and Ca doped CuYO2 from orthorhombic Cu2Y2O5 under a low O2 pressure atmosphere at above 1223 K. The obtained delafossite CuYO2 composed hexagonal and rhombohedral phases. The color of the CuYO2 powder was light brown and that of Ca-doped CuYO2 was light green. Diffraction peaks in the XRD pattern were slightly shifted by doping Ca for CuYO2, and these peaks shifted toward to a high diffraction angle with an increasing amount of doped Ca. From these results, we concluded that Ca doped delafossite CuYO2 could be obtained by thermal decomposition of a metal-citric acid complex.


2008 ◽  
Vol 43 (5) ◽  
pp. 1099-1105 ◽  
Author(s):  
Sa Lv ◽  
Jie Sheng ◽  
Shuang Zhang ◽  
Wendong Sun
Keyword(s):  

1981 ◽  
Vol 97 (2) ◽  
pp. 313-318
Author(s):  
J. P. Mittal ◽  
P. K. Ghosh

SummaryThe influence of various factors like breed, season, level of nutrition, age and body weight was studied in indigenous (Marwari and Magra) and exotic (Corriedale) rams in respect of semen quality and sexual behaviour under the arid conditions of Jodhpur in the Indian desert. None of these factors except breed and level of nutrition affected semen quality. The breeds differed significantly only in respect of percentage abnormal sperms. The values for all the physical characteristics except sperm concentrations wore slightly lower in the Corriedale. Supplementary concentrate feeding resulted in significantly higher concentrations only of fructose and citric acid in the semen. The physical characteristics of the semen were only slightly superior in the feed-supplemented group of animals. The breeds differed significantly in respect of libido characteristics, with the Corriedale exhibiting the longest reaction time and the lowest number of matings in 30 min. These characteristics were, however, not affected by the other factors mentioned above.


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