Low temperature H2 production from ammonia using ruthenium-based catalysts: Synergetic effect of promoter and support

Abstract

a b s t r a c tLow temperature hydrogen production via ammonia decomposition is achieved by the synergetic combination of a highly conductive support and an electron donating promoter in a ruthenium-based system, with activity at temperatures as low as 450 K. The high conductivity of graphitized carbon nanotubes allows for greater electronic modification of the ruthenium nanoparticles by cesium located in close proximity but without direct contact, avoiding the blockage of the active sites. This development of low temperature catalytic activity represents a breakthrough toward the use of ammonia as chemical storage for in-situ hydrogen production in fuel cells.

H2 Production via Ammonia Decomposition Using Non-Noble Metal Catalysts: A Review

“…Catalytic cracking or decomposition of ammonia is the reverse reaction of the Haber-Bosch synthesis of ammonia, one of the most extensively researched processes over the past 150 years [17]. Ammonia is commonly used in the production of fertilisers and household cleaning products and therefore has well-established protocols for its handling and usage and a safe existing transportation and distribution network [12].…”

“…and CNTs due to the high conductivity [17]. Due to the limited number of studies of cobalt catalysts for ammonia decomposition, it is difficult to draw concrete conclusions about the most active cobalt particle size, although in general the highest rates of conversion (at 500°C) have been reported within the size range 10-20 nm [44,56].…”

“…Ru h À1 at 430°C) [2,17]. The low temperature activity can be further improved by the addition of an electron donating promoter such as cesium (7870 mol H 2 mol…”

“…Ru h À1 at 370°C) [3,17,19,20]. Furthermore, the synergetic effect of cesium and the [5][6][7][8][9][10].…”

“…Furthermore, the synergetic effect of cesium and the [5][6][7][8][9][10]. Circle hydrogen under different conditions, triangle hydrocarbons, pentagon materials for H 2 physisorption, right angle triangle metal hydrides, diamond water, square ammonia and related compounds graphitisation of the carbon nanotubes support on the ruthenium nanoparticles have recently enabled the decomposition of ammonia at temperatures as low as 180°C, representing a breakthrough in the field [17]. Despite the excitement of these results, the cost and scarcity of ruthenium and cesium as shown in Fig.…”