Ru-Based Catalysts for H2 Production from Ammonia: Effect of 1D Support

This study reveals the effect of the catalytic 1D supports (carbon, ceria, alumina and titanate) for ruthenium particles on the low temperature release of hydrogen from ammonia. While the state-of-art literature presents Ru/carbon nanotubes (CNT) as the most active catalyst, we found in this work that ruthenium supported on ceria nanorods (Ru/CeO2) catalyst exhibited activity over 8 times higher than the Ru/CNT counterpart system. This enhanced activity is believed to be related to a strong metal-support interaction on the Ru/CeO2 catalysts promoting the formation of small (~ 3 nm) Ru particles. Addition of sodium as a promoter leads to the formation of smaller Ru particle sizes in addition to the modification of the electronic environment of Ru, enhancing the ammonia decomposition activity at low temperatures. This effect is particularly noticeable in the Ru-Na/CNT catalysts, facilitated by the high conductivity of the support, allowing distant electronic modification of the Ru active sites. This work provides novel insights in designing catalysts for hydrogen production from ammonia in our effort to enable the long-term energy storage in chemical bonds.

本研究揭示了钌颗粒的一维催化载体（碳、二氧化铈、氧化铝和钛酸盐）对氨低温释放氢气的影响。虽然现有文献表明钌/碳纳米管（CNT）是活性最高的催化剂，但我们在这项工作中发现，负载在二氧化铈纳米棒上的钌（Ru/CeO₂）催化剂的活性比Ru/CNT对应体系高出8倍以上。这种增强的活性被认为与Ru/CeO₂催化剂上强烈的金属 - 载体相互作用有关，这种相互作用促进了小（约3纳米）Ru颗粒的形成。添加钠作为助剂除了改变Ru的电子环境外，还导致形成更小的Ru颗粒尺寸，从而提高了低温下氨分解的活性。这种效应在Ru - Na/CNT催化剂中尤为明显，这得益于载体的高导电性，使得Ru活性位点能够进行远程电子修饰。这项工作为设计用于从氨中制氢的催化剂提供了新的见解，有助于我们实现化学键中的长期能量存储。