Papers by Keyword: Catalyst

Abstract: A novel kind of AgNPs catalyst was synthesized by in-situ reduction method using poly(2-acrylamido-2-methyl propyl sulfonic acid-co-2-hydroxyethyl methclate) [short as P(AMPS-co-HEMA)] hydrogel as matrices and AgNO₃ as a metal precursor. The structure of the composite hydrogel was characterized by Scan Electrical Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The results showed that AgNPs were binded with end group and most of the particles were isolated and uniformly distributed on the P(AMPS-co-HEMA). The catalytic properties in the reduction reaction of 4-nitrophenol(shorted as 4-NP) to 4-aminophenol(shorted as 4-AP) were studied in detail, and the result showed that conversion rate and conversion efficiency attained 97.56% and 0.9671 mmol/g·min when the amount of AgNPs was 9mg, [NaBH₄] was 2.0×10⁻¹ mol/L, [4-NP] was 2.0×10⁻² mol/L and the total volume of solution was 50 mL, respectively.

Abstract: A mild synthetic process using formic acid as the reduction agent was applied to prepare 40 wt% Pt/carbon aerogel (CA) electrocatalyst. The as-prepared sample was characterized by transmission electron microscopy (TEM) and electrochemical measurements. The results exhibit Pt nanoparticles with narrow particle size distribution are dispersed throughout carbon aerogel structure. Moreover, the Pt/CA catalyst has smaller Pt nanoparticle mean size than Johnson Matthey HiSpec^TM 4000 (JM4000). The electrochemical measurement results indicate that the Pt/CA catalyst with Pt loading of 40 wt% possesses similar electrochemical surface area (ESA) value and oxygen reduction reaction (ORR) activity as JM4000.

Abstract: In this paper, the influence of catalyst on the formation of ethyl lactate from glucose and ethanol was investigated. Among the catalysts tested, Co and Cu₂O shows the catalytic activity for the ethyl lactate production and obtained the same 7.2% yield of ethyl lactate. The stability of Co before and after the reaction was suitable for the transformation. The effect of reaction time was also studied over Co.

Abstract: In this paper, the novel structure of carbon nanocoils were synthesized successfully by catalytic thermal decomposition of acetylene in CVD reactor under inert atmospheric pressure. Fe as a catalyst coated alumina beads used as substrate , both were placed inside a cylindrical shape stainless steel mesh SSC and located at the mid of CVD reactor. Preliminary study of application of prepared carbon nanocoil in synthesis of photodiode showed that the photodiode has a good rectification and the forward current obeys to tunneling-recombination model.

Abstract: A removable catalyst muffler is designed and applied according to the characteristics of general 125ml motorcycle muffler. It has advantages of convenient disassembling, simpler catalyst replacement and low cost of installation and maintenance.

Abstract: This paper presents the fabrication and characterization of platinum-based catalytic microcombustor. The platinum catalyst was deposited onto type-304 stainless steel using the wet impregnation method. The stainless steel undergoes controlled conversion coating treatment in sulfuric acid solution to increase the porosity of its surface before the deposition of the platinum catalyst. The scanning electron microscopy result showed that the porosity on the stainless steel surface will depend on the length of treatment time in the sulfuric acid solution. The surface porosity increased as the treatment time increases. The stainless steel surface morphology changed from smooth to ‘cracked-mud’ morphology after treatment in sulfuric acid solution. The treatment time also provide significant effect to the amount of platinum deposited on the stainless steel surface. The energy dispersive x-ray analysis showed that the amount of deposited platinum for 10 seconds of treatment time was 0.68 wt%, whereas those for 20 and 30 seconds were 0.87 wt% and 1.10 wt%, respectively. Liquefied petroleum gas-air combustion result showed that the flame completely submerged inside the microcombustor with a catalyst, whereas portions of flame can be observed at the exhaust for the microcombustor without a catalyst. The minimum air-to-fuel ratios before the combustion blow-out for 10, 20, and 30 seconds of treatment time was 0.5, 0.4, and 0.3 respectively.

Abstract: Selective Catalytic Reduction catalyst (Cu-Mn/CSC) was derived from coconut shell carbon (CSC). The bimetallic catalysts, Copper and Manganese (Cu-Mn), were deposited onto CSC using wet impregnation technique while the calcination stage was performed under low temperature ambient air. The samples were then characterized using nitrogen adsorption-and-desorption, carbon dioxide temperature-programmed desorption, ammonia temperature-programmed desorption, hydrogen temperature-programmed reduction as well as scanning electron microscopy. The results showed that the synthesis process increased the external surface area and regulated the distribution of slit-shape pores on Cu-Mn/CSC. Besides, Cu-Mn was found to be reduced and the surface has more acidic groups compared to basic. These findings indicated the potential of using CSC as a precursor for NOx-Selective Catalytic Reduction catalyst.

Abstract: A new sensor with Pt and Ag mixture paste on the surface to act as the sensing electrode (Ag) and catalyst (Pt) to oxidized SO₂ to SO₃ for sulfur dioxide was fabricated. The effect of auxiliary phase on the sensing properties has been investigated and the device with auxiliary phase showed better performance and the effect of operating temperature has also been studied. It shown that 500°C would be more suitable than 600°C for the device gas test.

Abstract: Montmorillonite pillared by mixing Fe, Fe-Cr, Al-Fe and Cu-Al complexes was investigated for their catalytic activities for Water Gas Shift Reaction (WGSR). Element chemical analysis showed that the content of Fe, Fe-Cr, Al-Fe catalysts were 26.93%, 31.03%, 28.20%, respectively. Compared with the traditional shift catalyst, in the same shift condition, we can use the PILC catalysts to substitute. Using PILC catalysts can accurately control the constitution of synthesis gas over changing shift rate.

Abstract: Catalytic hydrodechlorination (HDC) is an innovative means of transforming chlorinated waste streams into a recyclable product. Hydrodehalogenation of 4-tert-butyl-1-chloro-2-nitrobenzene over Raney nickel catalyst has been investigated. The influence of different parameters, such as reaction solution, bases type, temperature and pressure are explored. Using Raney nickel as catalyst, methanol and water (v: v=4:1) as the reaction solution, ammonium acetate as the addictive, the ratio of ammonium acetate and 4-tert-butyl-1-chloro-2-nitrobenzene is 1:1, temperature 140 °C and pressure 3.0 Mpa, the highest efficiency can be achieved on hydride-chlorination of 4-tert-butyl-1-chloro-2-nitrobenzene. We find that a rather high catalytic activity can be retained by adding water.