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Surface or bulk promotion of ZrO2-based catalysts with Bi2O3 facilitates the removal of lattice oxygen from ZrO2 under reductive conditions resulting in the formation of coordinatively unsaturated Zr cations. The catalysts demonstrated an industrially relevant propene yield at 600 °C. The results highlight the importance of the usage of suitable promoters for controlling catalyst performance. [ABSTRACT FROM AUTHOR]

Conversion of propane or butanes from natural/shale gas into propene or butenes, which are indispensable for the synthesis of commodity chemicals, is an important environmentally friendly alternative to oil-based cracking processes. Herein, we critically analyse recent developments in the non-oxidative, oxidative, and CO2-mediated dehydrogenation of propane and isobutane to the corresponding olefins over metal oxide catalysts. Particular attention is paid to (i) comparing the developed catalysts in terms of their application potential, (ii) structure–activity–selectivity relationships for tailored catalyst design, and (iii) reaction-engineering aspects for improving product selectivity and overall process efficiency. On this basis, possible directions for further research aimed at the development of inexpensive and environmentally friendly catalysts with industrially relevant performance were identified. In addition, we provide general information regarding catalyst preparation and characterization as well as some recommendations for carrying out non-oxidative and CO2-mediated dehydrogenation reactions to ensure unambiguous comparison of catalysts developed in different studies. [ABSTRACT FROM AUTHOR]

Single-atom catalysts (SACs), possessing a uniform metal site structure, are a promising class of materials for selective oxidations of hydrocarbons. However, their design for targeted applications requires careful choice of metal-host combinations and suitable synthetic techniques. Here, we report iron atoms stabilised on defective hexagonal boron nitride (h-BN) via mechanochemical activation in a ball mill as an effective catalyst for propylene production via N 2 O-mediated oxidative propane dehydrogenation (N 2 O-ODHP), reaching 95% selectivity at 6% propane conversion and maintaining stable performance for 40 h on stream. This solvent-free synthesis allows simultaneous carrier exfoliation and surface defect generation, creating anchoring sites for catalytically-active iron atoms. The incorporation of a small metal quantity (0.5 wt%) predominantly generates a mix of atomically-dispersed Fe 2+ and Fe 3+ species, as confirmed by combining advanced microscopy and electron paramagnetic resonance, UV-vis and X-ray photoelectron spectroscopy analyses. Single-atom iron favours selective propylene formation, while metal oxide nanoparticles yield large quantities of CO x and cracking by-products. The lack of acidic functionalities on h-BN, hindering coke formation, and firm stabilisation of Fe sites, preventing metal sintering, ensure stable operation. These findings showcase N 2 O-ODHP as a promising propylene production technology and foster wider adoption of mechanochemical activation as a viable method for SACs synthesis., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Surface or bulk promotion of ZrO 2 -based catalysts with Bi 2 O 3 facilitates the removal of lattice oxygen from ZrO 2 under reductive conditions resulting in the formation of coordinatively unsaturated Zr cations. The catalysts demonstrated an industrially relevant propene yield at 600 °C. The results highlight the importance of the usage of suitable promoters for controlling catalyst performance.