Oxidative dehydrogenation of isobutane to isobutene by pyrovanadates, M 2 V 2 O 7 , where M(II) = Mn, Co, Ni, Cu and Zn, and Co 2 VO 4 and ZnV 2 O 4 : The effect of gold nanoparticles

Han

et al. 2020

ACS Appl. Bio Mater.

Nanozymes with various activities have attracted much attention owing to their great potential in the fields of biochemical analysis and environmental monitoring. Herein, for the first time, granular Co2V2O7 particles were synthesized using a simple hydrothermal method with pH regulation, and the triple-enzyme (oxidase-like, peroxidase-like, and catalase-like) activities and catalytic mechanisms of the prepared particles were systematically studied. On the basis of the excellent oxidase-like and peroxidase-like activities of Co2V2O7 particles, respectively, a colorimetric biosensor for detecting glutathione in health products (linear range: 2.5–20 μM) and a fluorescent platform for detecting glucose in human serum (linear range: 0.1–80 μM) were established, both of which had good selectivity and reliability. In particular, the fluorescence detection system exhibited ultrahigh sensitivity for H2O2, with a linear range of 0.008–3.2 μM, and a detection limit (0.002 μM) far superior to most reported in the literature to date. Furthermore, a one-step strategy for glucose detection was established to replace the traditional complicated two-step detection method, resulting in a more convenient detection process. These findings indicate the significant application prospects of Co2V2O7 particles in the field of biocatalysis and provide useful information for the future development of cobalt vanadate nanomaterials as enzyme mimics.

Section: Introductionmentioning

confidence: 99%

Co₂V₂O₇Particles with Intrinsic Multienzyme Mimetic Activities as an Effective Bioplatform for Ultrasensitive Fluorometric and Colorimetric Biosensing

Han

et al. 2020

ACS Appl. Bio Mater.

“…It appeared that different metals doped on support may be suitable for good surface basicities for ethanol dehydrogenation. Many pieces of research on the reaction of alcohols using heterogeneous catalysts have focused principally on highly active noble metals, such as platinum [9] and gold [10][11][12]. Therefore, more lasting solutions based on cheap, harmless, and stable metals to replace noble metals would be appealing.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, more lasting solutions based on cheap, harmless, and stable metals to replace noble metals would be appealing. In this regard, the application of catalysts based on relatively inexpensive metals, including manganese [10], nickel [10,13,14], cobalt [13], copper [3,4,[14][15][16], vanadium [17,18], silver [19][20][21], and iron [22], are being increasingly explored for dehydrogenation under ambient conditions. Moreover, a few studies have used activated carbon for ethanol dehydrogenation [22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Dehydrogenation of Ethanol to Acetaldehyde over Different Metals Supported on Carbon Catalysts

2019

Recently, the interest in ethanol production from renewable natural sources in Thailand has been receiving much attention as an alternative form of energy. The low-cost accessibility of ethanol has been seen as an interesting topic, leading to the extensive study of the formation of distinct chemicals, such as ethylene, diethyl ether, acetaldehyde, and ethyl acetate, starting from ethanol as a raw material. In this paper, ethanol dehydrogenation to acetaldehyde in a one-step reaction was investigated by using commercial activated carbon with four different metal-doped catalysts. The reaction was conducted in a packed-bed micro-tubular reactor under a temperature range of 250–400 °C. The best results were found by using the copper doped on an activated carbon catalyst. Under this specified condition, ethanol conversion of 65.3% with acetaldehyde selectivity of 96.3% at 350 °C was achieved. This was probably due to the optimal acidity of copper doped on the activated carbon catalyst, as proven by the temperature-programmed desorption of ammonia (NH3-TPD). In addition, the other three catalyst samples (activated carbon, ceria, and cobalt doped on activated carbon) also favored high selectivity to acetaldehyde (>90%). In contrast, the nickel-doped catalyst was found to be suitable for ethylene production at an operating temperature of 350 °C.

Journal of Molecular Catalysis A: Chemical

“…There are numerous classes of cobalt vanadates such as Co 3 V 2 O 8 [16,17], Co 2 V 2 O 7 [18,19] and CoV 2 O 6 [20,21]. Many inquiries have been carried out on the synthesis routes of cobalt vanadates including precipitation [22], solid-state [23], sol-gel [24], hydrothermal [25,26] and electrospinning [27].…”

mentioning

confidence: 99%

Size controllable synthesis of cobalt vanadate nanostructures with enhanced photocatalytic activity for the degradation of organic dyes

Ghiyasiyan-Arani

Masjedi-Arani

Salavati‐Niasari

2016

108

Different types of cobalt vanadate nanostructures such as Co 3 V 2 O 8 , Co 2 V 2 O 7 and CoV 2 O 6 have been successfully prepared via a simple solid-state method. For the first time, cobalt vanadate nanostructures were synthesized via Schiff-base ligand and vanadyl sulfate as a capping agent and vanadium source, respectively. The effect of a Schiff-base ligand (N,N-Bis (salicylaldehyde) ethylenediamine = H 2 salen) as a capping agent, molar ratio of Co: H 2 salen and Co:V on type of products, morphology and size of cobalt vanadate nanoparticles was investigated to reach optimum condition. The as-prepared nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmittance electron microscopy (TEM), Fourier transform infrared (FT-IR) spectra, energy dispersive X-ray microanalysis (EDX) and ultraviolet-visible (UV-Vis) spectroscopy. This work is the first study on photocatalytic activity of cobalt vanadate nanostructures in different conditions. The influence of different parameters such as type of cobalt vanadate nanostructures, type of dye, size of particles and nanostructures dosage as a catalyst on photocatalytic activity of samples were studied.