Laser pyrolysis (LP) using a CO2 laser was used to rapidly heat Avicel cellulose char with and without doping by Na, K, Ca, Mg, Co, Ni, Cu, Pd, and Zn as their respective acetates in the uncharred cellulose. LP−molecular beam mass spectrometry (LP−MBMS) was used to probe the chemistry of the pyrolysis of the chars and to characterize the initial volatilized reacting plume of pyrolyzate. The mass spectra were deconvoluted by multivariant factor analysis (MVA). MVA revealed that, at the 1 wt % doping level, Cu did little to change the pyrolysis chemistry of cellulose char, among the other metals, Na, K, Ca, Mg, Co, Ni, and Zn did effect the pyrolysis chemistry, and Co and to a lesser extent Pd acted by a differing mechanism. A liquid N2 cold trap coated with diphenyldisulfide was used to understand the chemistry of the evolving pyrolyzate plume. The washings from this trap were analyzed by gas chromatography−mass spectrometry (GC−MS) allowing for speciation of both the chemically trapped radicals and the nonradical volatiles. It was clear that the species trapped had a much greater degree of methyl substitution than observed in the LP−MBMS. Radicals trapped included hydrogen, methyl, and phenyl but did not include cyclopentadienyl or benzyl. Zn, which was volatilzed by the LP, had the highest yield of radicals. In general, the cold-trapped 1 and 2 aromatics had a higher level of methyl substitution. Cu and Pd increase the formation of aromatic species during the pyrolysis of cellulose char and have a variable effect on radical production. Na, K, Mg, Ca, Co, and Ni suppress the formation of aromatic species and have a variable effect on radical production.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.