Direct methane activation by atomically thin platinum nanolayers on two-dimensional metal carbides

Efficient and direct conversion of methane to value-added products has been a long-term challenge in shale gas applications. Here, we show that atomically thin nanolayers of Pt with a single or double atomic layer thickness, supported on a two-dimensional molybdenum titanium carbide (MXene), catalyse non-oxidative coupling of methane to ethane/ethylene (C-2). Kinetic and theoretical studies, combined with in-situ spectroscopic and microscopic characterizations, demonstrate that Pt nanolayers anchored at the hexagonal close-packed sites of the MXene support can activate the first C-H bond of methane to form methyl radicals that favour desorption over further dehydrogenation and thus suppress coke deposition. At 750 degrees C and 7% methane conversion, the catalyst runs for 72 hours of continuous operation without deactivation and exhibits >98% selectivity towards C-2 products, with a turnover frequency of 0.2-0.6 s(-1). Our findings provide insights into the design of highly active and stable catalysts for methane activation and create a platform for developing atomically thin supported metal catalysts.

Automated summary

The study demonstrates that atomically thin Pt nanolayers supported on MXene can efficiently catalyze the conversion of methane to ethane/ethylene, operating for 72 hours at high temperatures with >98% selectivity, providing important insights into designing highly active and stable catalysts.