The invention discloses preparation of a 
ruthenium-modified Ir / C catalyst and application of the 
ruthenium-modified Ir / C catalyst to 
citral hydrogenization. The catalyst comprises an 
active carbon carrier, and an 
active component comprises Ir nano particles and Ru nano particles, wherein the 
carrying capacity of the Ir nano particles is 1.0 to 5.0 percent, and the 
carrying capacity of the Ru nano particles is 0 to 4.0 percent. The invention further discloses a preparation method of the 
ruthenium-modified Ir / C catalyst. The preparation method comprises the following steps: firstly, treating 
active carbon through 
nitric acid, then carrying the 
active component including 
iridium and auxiliary ruthenium to obtain a catalyst precursor, and carrying out 
drying and reducing. As Ru replaces part of Ir, the catalyst disclosed by the invention is lower in cost, and also has higher 
catalysis activity and selectivity; furthermore, the catalyst can be used indiscriminately for multiple times, so that the production cost is reduced. When the catalyst is applied to 
citral hydrogenization to synthesize 
nerol, the 
raw material conversion rate is 100 percent, and the 
nerol / 
geraniol selectivity is up to 98.0 percent; the reaction process is mild in condition, and can completely meet the industrial production requirement.