scholarly journals Acetylene hydrochlorination over boron-doped Pd/HY zeolite catalysts

RSC Advances ◽  
2019 ◽  
Vol 9 (52) ◽  
pp. 30335-30339 ◽  
Author(s):  
Lu Wang ◽  
Lizhen Lian ◽  
Haijun Yan ◽  
Feng Wang ◽  
Jide Wang ◽  
...  

B doping partly weakens carbon deposition and Pd2+ reduction, thus enhancing catalytic stabilities of Pd/HY catalysts for acetylene hydrochlorination.

2021 ◽  
Vol 10 (2) ◽  
pp. 58-62
Author(s):  
Yuni Susanti ◽  
Yeni Variyana

Initially, zeolite catalysts cannot be used for reactions involving hot liquid water, so it is necessary to modify the zeolite to be stable under these conditions. The synthesis of HY and hydrophobic zeolites aimed to determine the stability of zeolite in hot liquid water (HLW). The stability of zeolite in HLW is related to zeolite hydrophobicity. In this study, the main raw materials for the synthesis of HY zeolite were sodium aluminate (NaAlO2) and Ludox HS-40 by calcining the product at 350 oC for 1 hour. Furthermore, increasing the hydrophobicity of HY zeolite was carried out by modifying the external zeolite surface using organosilanes (aminopropyltriethoxysilane). The stability of two zeolites in HLW was set at 200 oC. Zeolite analysis used physical test and Fourier Transform-Infra Red (FTIR) Spectrometer. The results of the zeolite distribution in two phases confirmed that HY zeolite was completely dispersed in the water phase, while the zeolite one was dispersed in the organic phase. Moreover, the IR spectra of HY zeolite showed that the wide peak detection at wave number 720 cm-1 for beginning to disappear. This means that the HLW condition could be damaged to the d6r unit. Another result was shown by hydrophobic zeolite spectra with a stable peak for 72 hours. This indicates that the hydrophobic zeolite has thermal stability in HLW so that it can be used in chemical reaction catalytic applications that use on phase.


1992 ◽  
Vol 242 ◽  
Author(s):  
Takashi Tsuno ◽  
Takahiro Imai ◽  
Yoshiki Nishibayashi ◽  
Naoji Fujimori

ABSTRACTUndoped and boron-doped diamond epitaxial films were deposited on diamond(001) substrate by micro-wave plasma assisted chemical vapor deposition and their surfaces were studied by scanning tunneling microscopy in air. An atomic order resolution was confirmed for the observation.For the undoped epitaxial films, which showed 2×1 and 1×2 RHEED patterns, dimer type reconstruction was observed and it was considered that the growth occurs through the dimer row extension. In the case of B-doped films, the dimer reconstruction was also observed. However, 2×2 structure due to the absence of dimer was partially observed.The effect of boron concentration and methane concentration during epitaxial growth on the surface morphology were also studied. The morphology observed by STM became flatter, as the concentration of B-doping and methane concentration, during growth, increased.


1997 ◽  
Vol 469 ◽  
Author(s):  
H. Bracht ◽  
A. Rodriguez Schachtrup

ABSTRACTDiffusion of Au into dislocation-free and highly dislocated Si with high B-background doping levels has been investigated with the aid of neutron activation analysis in conjunction with mechanical sectioning. The high B-doping level causes extrinsic conditions, i.e., the hole concentration exceeds the intrinsic carrier concentration even at diffusion temperatures between 900°C and 1100°C. All profiles are accurately described on the basis of the kick-out diffusion model and a mechanism which takes into account segregation of Au at dislocations. Our analysis provides solubility data of Au in Si and effective diffusion coefficients related to interstitial Au and Si self-interstitials I. The dependence of these quantities on the B-background doping level is well described by the Fermi-level effect. This analysis supports singly positively charged states in p-type Si of Au on interstitial (Aui) and substitutional (Aus) sites and of Si self-interstitials. Successful fitting of additionally requires an acceptor level of Aus. The electrical properties deduced for Aui, Aus and I are summarized in Table 2. Au profiles in highly dislocated Si obtained especially after diffusion at 900° C give evidence of Au trapped at dislocations. From our preliminary experimental results we determine an enthalpy difference of 2.7 eV between Au on substitutional sites and Au captured at dislocations.


2020 ◽  
Vol 10 (1) ◽  
pp. 149-156
Author(s):  
I. Istadi ◽  
Teguh Riyanto ◽  
Luqman Buchori ◽  
Didi D. Anggoro ◽  
Andre W. S. Pakpahan ◽  
...  

The increase in energy demand led to the challenging of alternative fuel development. Biofuels from palm oil through catalytic cracking appear as a promising alternative fuel. In this study, biofuel was produced from palm oil through catalytic cracking using the modified HY zeolite catalysts. The Ni and Co metals were impregnated on the HY catalyst through the wet-impregnation method. The catalysts were characterized using X-ray fluorescence, X-ray diffraction, Brunauer–Emmett–Teller (BET), Pyridine-probed Fourier-transform infrared (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM) methods. The biofuels product obtained was analyzed using a gas chromatography-mass spectrometry (GC-MS) method to determine its composition. The metal impregnation on the HY catalyst could modify the acid site composition (Lewis and Brønsted acid sites), which had significant roles in the palm oil cracking to biofuels. Ni impregnation on HY zeolite led to the high cracking activity, while the Co impregnation led to the high deoxygenation activity. Interestingly, the co-impregnation of Ni and Co on HY catalyst could increase the catalyst activity in cracking and deoxygenation reactions. The yield of biofuels could be increased from 37.32% to 40.00% by using the modified HY catalyst. Furthermore, the selectivity of gasoline could be achieved up to 11.79%. The Ni and Co metals impregnation on HY zeolite has a promising result on both the cracking and deoxygenation process of palm oil to biofuels due to the role of each metal. This finding is valuable for further catalyst development, especially on bifunctional catalyst development for palm oil conversion to biofuels.


2008 ◽  
Vol 47 (17) ◽  
pp. 6538-6546 ◽  
Author(s):  
Dhanapalan Karthikeyan ◽  
Nachiyappan Lingappan ◽  
Bommasamudram Sivasankar ◽  
Navamoney John Jabarathinam
Keyword(s):  

1972 ◽  
pp. 2448-2450 ◽  
Author(s):  
Tadasuke HOSOYA ◽  
Haruo TAKAYA ◽  
Hideki OSHIO ◽  
Toshio MINEGISHI ◽  
Naoyuki TODO

2013 ◽  
Vol 452 ◽  
pp. 48-56 ◽  
Author(s):  
Silvana A. D’Ippolito ◽  
Laura B. Gutierrez ◽  
Carlos R. Vera ◽  
Carlos L. Pieck
Keyword(s):  

2016 ◽  
Vol 56 (7) ◽  
pp. 634-638 ◽  
Author(s):  
N. A. Zakarina ◽  
L. D. Volkova ◽  
N. A. Shadin ◽  
Ɵ. Dɵlelhanuly ◽  
V. P. Grigor’eva

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