Alumina (Al

2

O

3

) is widely used in the chemical industry as the catalyst and support due to its high specific surface area

abundant pore size distribution and chemical stability. However

the occurrence of hydration in water environment

result in outstanding decrease in specific surface area and collapse of pore structure. In this work

dodecyl phosphoric acid (PA) is used to modify the surface of Al

2

O

3

to obtain a series of hydrophobic material (Al

2

O

3

-PA). Based on XPS and NMR analysis

PA is chemically bonded on Al

2

O

3

to form P-O-Al bond. Furthermore

BET and WCA results display that Al

2

O

3

-1PA exhibits excellent the hydrophobicity and hydrothermal stability while maintains the pore structure. Take it as the substrate to support the Pd nanoparticles

the as-prepared Pd/Al

2

O

3

-PA shows the superior catalytic performance in the hydrogenation of phenol and anthraquinone relative to Pd/Al

2

O

3

indicating the accessibility of Pd sites after PA modification. Especially

the significantly enhanced stability is also obtained in four cycles for a

queous phenol hydrogenation. This can be ascribed that the PA modification inhibits the aggregation of Pd nanoparticles and the products adhesion in the reaction process. The extension of PA coatings to monolithic catalysts could expand their current capabilities in industrial applications and warrants ongoing investigation.