Formic acid (FA) can be considered a bridge between biomass and green fuels, as biomass can be oxidized to FA, followed by FA dehydration to CO for Fischer–Tropsch synthesis. In this work, a series of γ-Mo₂N-based catalysts used for FA dehydration was prepared by the facile pyrolysis of a Mo-containing precursor at different temperatures. It was found that the γ-Mo₂N-based catalysts exhibited high performance for FA dehydration to CO with a maximum selectivity of ∼99.8%, and the onset reaction temperature over the γ-Mo₂N-based catalysts was also much lower (100–200 °C) than those over conventional solid acid catalysts. In particular, the γ-Mo₂N obtained at a pyrolysis temperature of 625 °C exhibited the highest activity, which was followed by those of the catalysts obtained at 600, 650, and 700 °C, which was consistent with the acidities of these catalysts. However, the CO selectivity monotonically increased with the increase in the catalyst preparation temperature but decreased with the increase in the FA decomposition temperature. FA conversion decreased when the contact time between the catalyst and the FA was reduced, but conversely, the CO selectivity increased. The enhanced CO selectivity might be ascribed to dehydrogenation having comparatively lower kinetics than that of dehydration, and thus, compared to dehydration, dehydrogenation could be more apparently suppressed by the reduced contact time, resulting in a higher CO selectivity. Moreover, it was found that the γ-Mo₂N catalyst had no obvious deactivation for FA dehydration over the 20 h continuous operation period.

中文翻译：

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甲酸作为生物CO载体：选择性脱水与γ-沫₂在低温Ñ催化剂

甲酸（FA）可以被视为生物质和绿色燃料之间的桥梁，因为生物质可以被氧化成FA，然后由FA脱水成CO进行费托合成。在这项工作中，一系列γ-的Mo ₂用于FA脱水N基催化剂是通过在不同温度下含Mo前体的热解容易制备。结果发现，在γ-沫₂ N基催化剂显示出高的性能FA脱水为CO与~99.8％的最大选择性和发作反应温度在γ-沫₂ N基催化剂也低得多（比传统的固体酸催化剂高100–200°C）。具体地，γ-沫₂在625℃的热解温度下获得的N表现出最高的活性，其次是在600、650和700℃下获得的催化剂的活性，这与这些催化剂的酸度一致。然而，CO选择性随着催化剂制备温度的增加而单调增加，但随着FA分解温度的增加而单调降低。当催化剂和FA之间的接触时间减少时，FA转化率降低，但是相反，CO选择性增加。CO选择性的提高可能归因于具有比脱水动力学更低的动力学的脱氢，因此，与脱水相比，通过减少接触时间可以更明显地抑制脱氢，从而导致更高的CO选择性。此外，发现γ-Mo在连续运行20小时后，₂ N催化剂对FA的脱水没有明显的失活。