State Key Laboratory for Physical Chemistry of the Solid Surfaces, National Engineering Laboratory for Green Chemical Productions of Alcohols–Ethers–Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
Fushun Research Institute of Petroleum & Petrochemicals, SINOPEC, Fushun 113001, Liaoning, People's Republic of China
Hydrogen spillover on Ni–CsxH3−xPW12O40 (x = 0, 1, 2) double-function hydrocracking catalyst was studied by temperature-programmed desorption (H2-TPD and NH3/H2-TPD) and thermodynamic calculations. The results of H2-TPD show that the hydrogen adsorption amount on the two-component Ni–CsxH3−xPW12O40 (x = 0, 1, 2) catalysts is much greater than that on single-component catalysts, such as nickel, tungstophosphoric acid and its cesium salts. Moreover, the H+ content is related to the content of Ni–CsxH3−xPW12O40. The above phenomena can be explained by the spillover hydrogen H combining with H+ to form Hn+ (n = 2, 3). The results of NH3/H2-TPD can also indirectly prove the existence of Hn+. It is demonstrated by the theoretical calculation that the formation of Hn+ (n = 2, 3) from H and H+ is favorable in energy, and NH3 may combine with H3+ to form NH6+.