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Critical role of formaldehyde during methanol conversion to hydrocarbons.

ABSTRACT: Formaldehyde is an important intermediate product in the catalytic conversion of methanol to olefins (MTO). Here we show that formaldehyde is present during MTO with an average concentration of ~0.2?C% across the ZSM-5 catalyst bed up to a MeOH conversion of 70%. It condenses with acetic acid or methyl acetate, the carbonylation product of MeOH and DME, into unsaturated carboxylate or carboxylic acid, which decarboxylates into the first olefin. By tracing its reaction pathways of ¹³C-labeled formaldehyde, it is shown that formaldehyde reacts with alkenes via Prins reaction into dienes and finally to aromatics. Because its rate is one order of magnitude higher than that of hydrogen transfer between alkenes on ZSM-5, the Prins reaction is concluded to be the major reaction route from formaldehyde to produce dienes and aromatics. In consequence, formaldehyde increases the yield of ethene by enhancing the contribution of aromatic cycle.

SUBMITTER: Liu Y

PROVIDER: S-EPMC6443648 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature

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Critical role of formaldehyde during methanol conversion to hydrocarbons.

Liu Yue Y Kirchberger Felix M FM Müller Sebastian S Eder Moritz M Tonigold Markus M Sanchez-Sanchez Maricruz M Lercher Johannes A JA

Nature communications 20190401 1

Formaldehyde is an important intermediate product in the catalytic conversion of methanol to olefins (MTO). Here we show that formaldehyde is present during MTO with an average concentration of ~0.2 C% across the ZSM-5 catalyst bed up to a MeOH conversion of 70%. It condenses with acetic acid or methyl acetate, the carbonylation product of MeOH and DME, into unsaturated carboxylate or carboxylic acid, which decarboxylates into the first olefin. By tracing its reaction pathways of <sup>13</sup>C- ...[more]

PMID: 30931945

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