Phosphorus reaction with metal oxides

SAFETY PROFILE Poison by skin contact and subcutaneous routes. Human systemic effects by skin contact with very small amounts primary irritant, corrosive. Explodes on contact with potassium, white phosphorus. Ignites on contact with antimony. Vigorous reaction with metal oxides (e.g., silver oxide, lead(II) oxide, lead(IV) oxide, lead(II)(IV) oxide). When heated to decomposition it emits very toxic fumes of Cl" and Se. See also SELENIUM COMPOUNDS and CHLORIDES. 

In all of this early work the general observation was made that the successful operation of the process was greatly interfered with by the rapid deterioration of the catalyst. This seemed to depend in part upon impurities present in the acetylene (phosphorus and its compounds being particularly potent poisons) and also upon the deposit of carbon on the surface of the catalyst due to decomposition reactions. When metal oxides or compounds such as, for example, molybdic acid were used, deterioration appeared to be due at least in part to the partial reduction of these compounds. In most of these cases the activity of the catalyst was restored 107 by heating it in a current of air at high temperatures (600° C.). 

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