Modified Lanthanum Catalysts for Oxidative Chlorination of Methane

Abstract

Mixtures of LaOCl and LaCl 3 are promising catalysts for oxidative chlorination of methane to methyl chloride. The influence of metal dopants such as Co, Ni and Ce, which form stable chlorides under anticipated reaction conditions, on physicochemical and catalytic properties was explored. The presence of markedly redox-active dopants such as cobalt and cerium lead to a higher rate of methane conversion. However, the formed methyl chloride is strongly adsorbed and directly oxidized to CO leading to low methyl chloride selectivity. Doping with nickel weakens, in contrast, the interaction with methyl chloride leading to high methyl chloride selectivity.

Conversion of Methanol to Hydrocarbons: How Zeolite Cavity and Pore Size Controls Product Selectivity

“…Methyl halides may be formed either from methane by reaction with molecular halogens (see for example Refs [172][173][174][175][176]), or from biomass. [177] When considering natural gas as the source of higher hydrocarbons, methyl halides have the advantage that they may be formed directly from methane without the synthesis gas-forming step required for methanol synthesis, and with relatively high yields compared to other direct conversion processes.…”

Umwandlung von Methanol in Kohlenwasserstoffe: Wie Zeolith‐Hohlräume und Porengröße die Produktselektivität bestimmen

“…B. Lit. [172][173][174][175][176]) oder aus Biomasse gebildet werden. Wenn man Erdgas als Quelle hçherer Kohlenwasserstoffe betrachtet, haben Methylhalogenide den Vorteil, dass man sie direkt aus Methan bilden kann (ohne den für die Methanolsynthese notwendigen Zwischenschritt der Synthesegas-Herstellung), und dies zudem mit einer relativ hohen Ausbeute im Vergleich zu anderen direkten Umwandlungsprozessen.…”

Transformation of Methane to Propylene: A Two‐Step Reaction Route Catalyzed by Modified CeO2 Nanocrystals and Zeolites

“…[7] Only a few studies have been devoted to the oxidative chlorination of CH 4 to CH 3 Cl, although HCl is cheaper than HBr. Lercher and co-workers found that LaCl 3 was a superior catalyst for this reaction, which provided CH 3 Cl with a selectivity of around 55 % at a CH 4 conversion of 12 % at 748 K. [8] Herein, we present a novel catalytic route for the conversion of CH 4 to propylene via monohalogenomethane. Propylene is one of the most important bulk chemicals, and currently, it is mainly produced as a coproduct of ethylene through the cracking of naphtha.…”