In this study

diphenyl sulfide (Ph

2

S) was employed to prepare a series of Ph

2

S-modified Pd/C catalysts (Pd-Ph

2

S/C). Catalyst characterization carried out by Brunner-Emmet-Teller (BET)

energy dispersive spectrometer (EDS)

X-ray diffraction (XRD)

X-ray photoelectron spectroscopy (XPS) and CO chemisorption uptakemeasurements suggested a chemical interaction between Ph

2

S and Pd. The ligand was preferably absorbed on the active site of Pd metal but after increasing the amount of Ph

2

S

the adsorption of Ph

2

S on Pd metal tended to be saturated and the excess of Ph

2

S partially adsorbed on the activated carbon. A part of Pd atoms without adsorbing any Ph

2

S still existed

even for the saturated Pd-Ph

2

S/C catalyst. The Pd-Ph

2

S/C catalysts exhibited a good selectivity of

p

-chloroaniline (

p

-CAN) in the hydrogenation of

p

-chloronitrobenzene (

p

-CNB). However

the chemisorption between Ph

2

S and Pdwas not so strong that part of Ph

2

Swas leached fromPd-Ph

2

S/C catalyst during the hydrogenation

which caused the decline of the selectivity of

p

-CA

N over the used Pd-Ph

2

S/C catalyst. Resulfidation of the used Pd-Ph

2

S/C catalystwas effective to resume its stability

and the regenerated Pd-Ph

2

S/C catalyst could be reused for at least ten runs with a stable catalytic performance.