Discovery, Preparation, and Uses of Hydrogen

The reaction of a metal such as iron or zinc with a strong acid such as sulfuric or hydrochloric [shovra in Equation (10.5)] is still the most common way to produce hydrogen in the laboratory. It is also common to reverse the reaction between hydrogen and oxygen by carrying out the electrolysis of water, as represented 

The most common industrial preparation of hydrogen is the catalytic steam-hydrocarbon reforming process [Equations (10.7) and (10.8)]  

Aptly named, this process treats a mixture of hydrocarbons (propane, CjHg, is shoAvn as a representative example) from natural gas or crude oil with steam (700°C- 1000°C) over a nickel catalyst and reforms it into a mixture of CO and H2 gases, which is called synthesis gas, or just syngas. The second reaction is knovra as the water-gas shift reaction, perhaps because it shifts oxygen from one reactant to another and thereby adjusts the composition of the syngas. It is carried out at elevated temperatures (325-350°C) over an iron(III) oxide catalyst. 

Other catalysts afford different hydrocarbons. Note that all the preceding reactions require the use of metal catalysts. The research and development of more efficient catalysts and a better understanding of their roles is a topic of considerable 

The largest single use of hydrogen is for the production of ammonia by the Haber process [Equation (10.11)]  

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