Determining the Surface Structure of Silicated Alumina Catalysts via Isotopic Enrichment and Dynamic Nuclear Polarization Surface-Enhanced NMR Spectroscopy. Rankin, A. G M, Webb, P. B, Dawson, D. M, Viger-Gravel, J., Walder, B. J, Emsley, L., & Ashbrook, S. E The Journal of Physical Chemistry C, 121(41):22977–22984, October, 2017. Publisher: American Chemical Society
Determining the Surface Structure of Silicated Alumina Catalysts via Isotopic Enrichment and Dynamic Nuclear Polarization Surface-Enhanced NMR Spectroscopy [link]Paper  doi  abstract   bibtex   
Isotopic enrichment of 29Si and DNP-enhanced NMR spectroscopy are combined to determine the detailed surface structure of a silicated alumina catalyst. The significant sensitivity enhancement provided by DNP is vital to the acquisition of multinuclear and multidimensional experiments that provide information on the atomic-level structure of the species present at the surface. Isotopic enrichment not only facilitates spectral acquisition, particularly given the low (1.5 wt %) Si loading, but also enables spectra with higher resolution than those acquired using DNP to be obtained. The unexpected similarity of conventional, CP, and DNP NMR spectra is attributed to the presence of adventitious surface water that forms a sufficiently dense 1H network at the silica surface so as to mediate efficient polarization transfer to all Si species regardless of their chemical nature. Spectra reveal the presence of Si–O–Si linkages at the surface (identified as Q4(3Al)–Q4(3Al)) and confirm that the anchoring of the surfa...
@article{Rankin2017,
	title = {Determining the {Surface} {Structure} of {Silicated} {Alumina} {Catalysts} via {Isotopic} {Enrichment} and {Dynamic} {Nuclear} {Polarization} {Surface}-{Enhanced} {NMR} {Spectroscopy}},
	volume = {121},
	issn = {1932-7447},
	url = {http://pubs.acs.org/doi/abs/10.1021/acs.jpcc.7b08137},
	doi = {10.1021/acs.jpcc.7b08137},
	abstract = {Isotopic enrichment of 29Si and DNP-enhanced NMR spectroscopy are combined to determine the detailed surface structure of a silicated alumina catalyst. The significant sensitivity enhancement provided by DNP is vital to the acquisition of multinuclear and multidimensional experiments that provide information on the atomic-level structure of the species present at the surface. Isotopic enrichment not only facilitates spectral acquisition, particularly given the low (1.5 wt \%) Si loading, but also enables spectra with higher resolution than those acquired using DNP to be obtained. The unexpected similarity of conventional, CP, and DNP NMR spectra is attributed to the presence of adventitious surface water that forms a sufficiently dense 1H network at the silica surface so as to mediate efficient polarization transfer to all Si species regardless of their chemical nature. Spectra reveal the presence of Si–O–Si linkages at the surface (identified as Q4(3Al)–Q4(3Al)) and confirm that the anchoring of the surfa...},
	number = {41},
	journal = {The Journal of Physical Chemistry C},
	author = {Rankin, Andrew G M and Webb, Paul B and Dawson, Daniel M and Viger-Gravel, Jasmine and Walder, Brennan J and Emsley, Lyndon and Ashbrook, Sharon E},
	month = oct,
	year = {2017},
	note = {Publisher: American Chemical Society},
	keywords = {\#nosource},
	pages = {22977--22984},
}

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