Direct one-pot synthesis of delaminated layered zeolitic materials aims to create two-dimensionally confined catalysts for reactions involving sterically bulky reactants,which are too large to benefit from conventiona...Direct one-pot synthesis of delaminated layered zeolitic materials aims to create two-dimensionally confined catalysts for reactions involving sterically bulky reactants,which are too large to benefit from conventional three-dimensional confinement in micropores.As a prototypical system,several efforts have focused on the development of post-synthetic approaches for delamination of silica-rich MWW layered zeolite precursors.展开更多
Planar tetrapods ZnO (PTP-ZnO) or cross shaped tetrapod nanostructures were synthesized by a cethyltrimethylamonium hydroxide (CTAOH)-assisted hydrothermal method at low temperature (120°C). The XRD diffractogram...Planar tetrapods ZnO (PTP-ZnO) or cross shaped tetrapod nanostructures were synthesized by a cethyltrimethylamonium hydroxide (CTAOH)-assisted hydrothermal method at low temperature (120°C). The XRD diffractogram showed that the PTP-ZnO nanostructures showed a hexagonal wurtzite phase. The studies with high resolution transmission electron microscopy (HRTEM) and select area specific diffraction (SAED) revealed that the ZnO pods were single crystals and preferentially grew up along [002] direction. The growth mechanism of the CTAOH assisted-hydrothermal synthesized PTP-ZnO nanostructures is explained using the final shape guiding of materials nanostructured and surfactant-action theories.展开更多
基金Department of Energy,Office of Science,Basic Energy Sciences(DE-FG02-05ER15696)for supporting the catalysis and materials characterization aspects of this workthe Management and Transfer of Hydrogen via Catalysis Program funded by Chevron Corporation for supporting the materials synthesis work in this manuscript.
文摘Direct one-pot synthesis of delaminated layered zeolitic materials aims to create two-dimensionally confined catalysts for reactions involving sterically bulky reactants,which are too large to benefit from conventional three-dimensional confinement in micropores.As a prototypical system,several efforts have focused on the development of post-synthetic approaches for delamination of silica-rich MWW layered zeolite precursors.
文摘Planar tetrapods ZnO (PTP-ZnO) or cross shaped tetrapod nanostructures were synthesized by a cethyltrimethylamonium hydroxide (CTAOH)-assisted hydrothermal method at low temperature (120°C). The XRD diffractogram showed that the PTP-ZnO nanostructures showed a hexagonal wurtzite phase. The studies with high resolution transmission electron microscopy (HRTEM) and select area specific diffraction (SAED) revealed that the ZnO pods were single crystals and preferentially grew up along [002] direction. The growth mechanism of the CTAOH assisted-hydrothermal synthesized PTP-ZnO nanostructures is explained using the final shape guiding of materials nanostructured and surfactant-action theories.
