TY - JOUR
T1 - Speciation of copper diffused in a bi-porous molecular sieve
AU - Huang, C. H.
AU - Wang, H. Paul
AU - Wei, Y. L.
AU - Chang, J. E.
N1 - Funding Information:
This research was supported by the Taiwan National Science Council, Bureau of Energy and the Excellence Project of the National Cheng Kung University. We thank J.F. Lee and Y.M. Yang of the Taiwan National Synchrotron Radiation Research Center (NSRRC) for their EXAFS and XANES experimental assistances. The beam time provided by the NSRRC is also appreciated.
PY - 2010/7/1
Y1 - 2010/7/1
N2 - To better understand diffusion of copper in the micro- and mesopores, speciation of copper in a bi-porous molecular sieve (BPMS) possessing inter-connecting 3-D micropores (0.50-0.55 nm) and 2-D mesopores (4.1 nm) has been studied by X-ray absorption near edge structure (XANES) spectroscopy. It is found that about 77% (16% of CuO nanoparticles and 61% of CuO clusters) and 23% (CuOads) of copper can be diffused into the meso- and micropores, respectively, in the BPMS. At least two diffusion steps in the BPMS may be involved: (i) free diffusion of copper in the mesopores and (ii) diffusion-controlled copper migrating into the micropores of the BPMS. The XANES data also indicate that diffusion rate of copper in the BPMS (4.68 × 10-5g/s) is greater than that in the ZSM-5 (1.11 xlO-6g/s) or MCM-41 (1.17xlO-5g/s).
AB - To better understand diffusion of copper in the micro- and mesopores, speciation of copper in a bi-porous molecular sieve (BPMS) possessing inter-connecting 3-D micropores (0.50-0.55 nm) and 2-D mesopores (4.1 nm) has been studied by X-ray absorption near edge structure (XANES) spectroscopy. It is found that about 77% (16% of CuO nanoparticles and 61% of CuO clusters) and 23% (CuOads) of copper can be diffused into the meso- and micropores, respectively, in the BPMS. At least two diffusion steps in the BPMS may be involved: (i) free diffusion of copper in the mesopores and (ii) diffusion-controlled copper migrating into the micropores of the BPMS. The XANES data also indicate that diffusion rate of copper in the BPMS (4.68 × 10-5g/s) is greater than that in the ZSM-5 (1.11 xlO-6g/s) or MCM-41 (1.17xlO-5g/s).
UR - http://www.scopus.com/inward/record.url?scp=78650282779&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78650282779&partnerID=8YFLogxK
U2 - 10.1016/j.nima.2009.10.134
DO - 10.1016/j.nima.2009.10.134
M3 - Article
AN - SCOPUS:78650282779
SN - 0168-9002
VL - 619
SP - 102
EP - 104
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
IS - 1-3
ER -