Challenges and Opportunities of Ru-Based Catalysts toward the Synthesis and Utilization of Ammonia

Abstract

Ammonia is an important chemical for synthesized fertilizers traditionally and for a potential energy vector increasingly. Industrial ammonia synthesis through the Haber–Bosch process is energy-intensive and requires advanced materials to catalyze ammonia synthesis under mild conditions, whereas the utilization of ammonia as a hydrogen carrier via ammonia decomposition is facing a similar situation as well. The developed second-generation Ru-based catalysts performs superior activities over commercial Fe- or Ni-based catalysts; however, it remains challenging to construct effective Ru catalysts to achieve the usage of Ru metal affordably as well as further understanding the nature of Ru catalysis. This Perspective summarizes the recent contributions in engineering Ru-based catalysts via various strategies and related catalysis in ammonia synthesis and decomposition, and it discusses the similarities and differences of Ru catalysis in these reactions. Finally, an overview of this area and opportunities for further investigation are also provided.

Insight into rare-earth-incorporated catalysts: The chance for a more efficient ammonia synthesis

“…However, due to the high price of Ru, the commercial use of Ru is severely limited. The market price of Ru was 1600 USD/kg in 2015 and increased to 18,500 USD/kg in 2021 [135]. To promote the revolution of the ammonia industry, it is urgent to increase the atom utilization of Ru in the catalysts.…”

Y-Doped BaCeO3 Perovskite-Supported Ru Catalysts for COx-Free Hydrogen Production from Ammonia: Effect of Strong Metal–Support Interactions

“…The global warming crisis caused by fossil fuel combustion and CO 2 emissions has motivated the development of sustainable energy systems based on carbon-free resources. Hydrogen is considered a clean energy source because it generates H 2 O as the sole byproduct. , However, the low volumetric energy density of H 2 gas (14 kg H 2 ·m –3 at 200 bar) and the expensive liquefaction process limit its storage and transportation capabilities for practical applications. , Ammonia (NH 3 ) has attracted considerable attention as a promising H 2 carrier because of its many advantages: (1) high volumetric (121 kg H 2 ·m –3 at 10 bar) and gravimetric (17.8 wt %) H 2 densities; (2) easy liquefaction; and (3) carbon-free chemical. − However, the demand for CO x -free H 2 production from NH 3 requires the development of efficient catalysts for NH 3 decomposition.…”

Atomic-Layer-Deposition Derived Pt subnano Clusters on the (110) Facet of Hexagonal Al2O3 Plates: Efficient for Formic Acid Decomposition and Water Gas Shift

“…With excessive consumption of traditional petroleum-based fuels, the issue of energy shortage has received more and more attention these years. Considerable efforts have been devoted to the kind of energy that is renewable. − Hydrogen is regarded as a green energy carrier and a key to achieve a low-carbon energy economy because its combustion only generates water − significantly reducing greenhouse gas emission and lowering environmental impact. − Up until now, the production of green hydrogen should be held utilizing new production strategies that allow for its large-scale applications in industry process, including transportation, fuel cell, aerospace industries, and green power generation. ,, Many studies have been focused on catalytic reactions to produce hydrogen especially for improving catalytic efficiency to satisfy increasing global hydrogen demands. − …”