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1.
Angew Chem Int Ed Engl ; 63(13): e202317660, 2024 Mar 22.
Article in English | MEDLINE | ID: mdl-38298160

ABSTRACT

Coordinated manganese (Mn) electrocatalysts owing to their electronic structure flexibility, non-toxic and earth abundant features are promising for electrocatalytic reactions. However, achieving selective hydrogen peroxide (H2 O2 ) production through two electron oxygen reduction (2e-ORR) is a challenge on Mn-centered catalysts. Targeting this goal, we report on the creation of a secondary Mn(II)-coordinated active environment with reactant enrichment effect on boundary-rich porous carbon-based electrocatalysts, which facilitates the selective and rapid synthesis of H2 O2 through 2e-ORR. The catalysts exhibit nearly 100 % Faradaic efficiency and H2 O2 productivity up to 15.1 mol gcat -1 h-1 at 0.1 V versus reversible hydrogen electrode, representing the record high activity for Mn-based electrocatalyst in H2 O2 electrosynthesis. Mechanistic studies reveal that the epoxide and hydroxyl groups surrounding Mn(II) centers improve spin state by modifying electronic properties and charge transfer, thus tailoring the adsorption strength of *OOH intermediate. Multiscale simulations reveal that the high-curvature boundaries facilitate oxygen (O2 ) adsorption and result in local O2 enrichment due to the enhanced interaction between carbon surface and O2 . These merits together ensure the efficient formation of H2 O2 with high local concentration, which can directly boost the tandem reaction of hydrolysis of benzonitrile to benzamide with nearly 100 % conversion rate and exclusive benzamide selectivity.

2.
Angew Chem Int Ed Engl ; 62(19): e202302466, 2023 May 02.
Article in English | MEDLINE | ID: mdl-36892310

ABSTRACT

Ethylene glycol is a useful organic compound and chemical intermediate for manufacturing various commodity chemicals of industrial importance. Nevertheless, the production of ethylene glycol in a green and safe manner is still a long-standing challenge. Here, we established an integrated, efficient pathway for oxidizing ethylene into ethylene glycol. Mesoporous carbon catalyst produces H2 O2 , and titanium silicalite-1 catalyst would subsequently oxidize ethylene into ethylene glycol with the in situ generated H2 O2 . This tandem route presents a remarkable activity, i.e., 86 % H2 O2 conversion with 99 % ethylene glycol selectivity and 51.48 mmol gecat -1 h-1 production rate at 0.4 V vs. reversible hydrogen electrode. Apart from generated H2 O2 as an oxidant, there exists ⋅OOH intermediate which could omit the step of absorbing and dissociating H2 O2 over titanium silicalite-1, showing faster reaction kinetics compared to the ex situ one. This work not only provides a new idea for yielding ethylene glycol but also demonstrates the superior of in situ generated H2 O2 in tandem route.

3.
Chem Commun (Camb) ; 58(37): 5626-5629, 2022 May 05.
Article in English | MEDLINE | ID: mdl-35438094

ABSTRACT

Here we report on the facile formation of asymmetric heterojunctions between laterally size different 2D flakes, which leads to a prominent gradient in charge distribution at the nanocontact interface and triggers ionic diode-like transport behaviour with a rectification ratio of 110.

4.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(11): 3096-9, 2015 Nov.
Article in Chinese | MEDLINE | ID: mdl-26978916

ABSTRACT

The biological drug of the calf-blood dialysate has various pharmacological effects. It can promote the oxygen and glucose uptake for the hypoxia cells, and has beneficial effects on the malfunction of the blood circulation and trophic disturbances in the brain, and the impairment of peripheral blood circulation. Furthermore, it is favorable to wound healing and can regulate the central nervous system. Adenosine monophosphate (AMP) is a main active ingredient of the biological drug. In this report, a fluorescence resonance energy transfer (FRET) sensor has been developed with ß-CD-capped ZnS QDs as energy donor and 3-hydroxyflavone (3-HF) as energy acceptor. The results showed that AMP can lead to the fluorescence quenching of the FRET sensor at 526 nm, and the Stern-Volmer curve between the fluorescence quenching and the concentrations of AMP present a satisfactory linearity with the correlation coefficient of 0.996. The developed sensor has successfully applied for determination of the AMP in the biological drug.


Subject(s)
Adenosine Monophosphate/analysis , Biological Products/analysis , Fluorescence Resonance Energy Transfer , Animals , Cattle
5.
Article in English | WPRIM (Western Pacific) | ID: wpr-282450

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the clinical effect of Liqi Kuanxiong Huoxue method LKH, traditional Chinese medicine, TCM therapeutic method for regulating qi, relieving chest stuffiness and promoting blood circulation) in treating patients with cardiac syndrome X (CSX).</p><p><b>METHODS</b>The prospective, non-randomized controlled study was conducted on 51 selected patients with CSX, who were non-randomly assigned to 2 groups, the treated group treated with LKH in addition to the conventional treatment (32 patients), and the control group treated with conventional treatment (19 patients) like nitrate, diltiazem hydrochloride, etc. The treatment course was 14 days. The changes of such symptoms as angina pectoris, TCM syndrome and indexes of treadmill exercise test before and after treatment were observed.</p><p><b>RESULTS</b>After treatment, such symptoms as chest pain and stuffy feeling and palpitation in the treated group were improved more than those in the control group (P<0.05); the total effective rate on angina pectoris and TCM syndrome in the treated group was better than that in the control group (P<0.05). The treadmill exercise test showed that the maximal metabolic equivalent (Max MET), the time of angina onset and ST segment depression by 0.1 mV were obviously improved after treatment in both groups, but the improvement in the treated group was better than that in the control group respectively (P<0.05).</p><p><b>CONCLUSION</b>The LKH method could reduce the frequency of angina attacks and improve the clinical condition of patients with CSX.</p>


Subject(s)
Female , Humans , Male , Middle Aged , Blood Circulation , Drug Combinations , Drugs, Chinese Herbal , Therapeutic Uses , Exercise Test , Microvascular Angina , Diagnosis , Therapeutics , Qi , Thorax , Treatment Outcome
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