Hydrogen halides safety

The addition of a gas to a reaction mixture (commonly the hydrogen halides, fluorine, chlorine, phosgene, boron trifluoride, carbon dioxide, ammonia, gaseous unsaturated hydrocarbons, ethylene oxide) requires the provision of safety precautions which may not be immediately apparent. Some of these gases may be generated in situ (e.g. diborane in hydroboration reactions), some may be commercially available in cylinders, and some may be generated by chemical or other means (e.g. carbon dioxide, ozone). An individual description of the convenient sources of these gases will be found under Section 4.2. 

Most researehers use supported monometallie Pd nanopartieles based catalysts for this direct synthesis proeess. However in these reaetions generally aeid and/or halide promoters are used to avoid the non-selective water formation through hydrogen peroxide decomposition and hydrogenation (routes C D in Fig. lb). Another route that heavily compromises the safety of this direet synthesis is the explosive formation water from H2 and O2 and this route ean be avoided by operating below the explosive limits by using very dilute mixtures of H2 and O2. Hutchings and co-workers have reported supported Pd based bimetallic nanoalloys... 

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