Although various Pd/C catalysts have been applied in the direct synthesis of H2O2, unsatisfactory H2O2 yields have been achieved. We systematically investigated the effect of heat treatment on the physicochemical properties of Pd/C catalyst, and thereby on the catalytic performance in the direct synthesis of H2O2. Pd/C catalysts prepared by the incipient wetness method were subjected to different heat treatments and applied in H2O2 synthesis. The calcination temperature was found to have a key role in determining the Pd nanoparticle (NP) size; calcination at 523 K yielded highly oxidized and small Pd NPs corresponding to the sub-nano domain (1.4-2.5 nm). This Pd/C catalyst is superior not only in promoting H2O2 formation, but also in suppressing the subsequent unfavorable H2O2 decomposition and hydrogenation, which explains its excellent H2O2 productivity (as high as 4,443mmol H2O2/g Pd·h) and selectivity (94.5%). On the other hand, the reaction performance of the Pd/C catalysts calcined at a higher temperature (673 K) or reduced under hydrogen was sharply reduced owing to the formation of larger Pd NPs or the enhancement of the metallic nature of Pd, respectively. The amount of residual Cl ion on Pd/C catalyst after heat treatment also had an impact on the catalytic activity as it affected the pH of reaction solution. These results clearly demonstrate that an efficient Pd/C catalyst can be realized by fine tuning the conditions of heat treatment during catalyst preparation.

Direct Synthesis of H2O2 Pd/C Incipient Wetness Heat Treatment Nanoparticle

Goor G, Glenneberg J, Jacobi S, Hydrogen Peroxide in Ullmann’s Encycl. Ind. Chem., Wiley-VCH Verlag GmbH, Weinheim (2012).
Wilson NM, Bregante DT, Priyadarshini P, Flaherty DW, Catalysis, 29, 122 (2017)
Samanta C, Appl. Catal. A: Gen., 350(2), 133 (2008)
Flaherty DW, ACS Catal., 8, 1520 (2018)
PERP Report - Propylene Oxide 02/03-8, Nexant, New York (2003).
Ab Rahim MH, Forde MM, Jenkins RL, Hammond C, He Q, Dimitratos N, Lopez-Sanchez JA, Carley AF, Taylor SH, Willock DJ, Murphy DM, Kiely CJ, Hutchings GJ, Angew. Chem.-Int. Edit., 52, 1280 (2013)
Edwin NN, Piccinini M, Pritchard JC, He Q, Edwards JK, Carley AF, Moulijn JA, Kiely CJ, Hutchings GJ, Chem-CatChem, 1, 479 (2009)
Edwards JK, Freakley SJ, Carley AF, Kiely CJ, Hutchings GJ, Accounts Chem. Res., 47, 845 (2014)
Menegazzo F, Signoretto M, Ghedini E, Strukul G, Catalysts, 9, 251 (2019)
Ranganathan VSS, Catalysts, 8, 379 (2018)
Tu WF, Li XL, Wang RQ, Malhi HS, Ran JY, Shi YL, Han YF, J. Catal., 377, 494 (2019)
Lewis RJ, Hutchings GJ, ChemCatChem, 11, 298 (2019)
Selinsek M, Deschner BJ, Doronkin DE, Sheppard TL, Grunwaldt JD, Dittmeyer R, ACS Catal., 8, 2546 (2018)
Chung YM, Korean Chem. Eng. Res., 53(2), 262 (2015)
Wilson NM, Flaherty DW, J. Am. Chem. Soc., 138(2), 574 (2016)
Freakley SJ, He Q, Harrhy JH, Lu L, Crole DA, Morgan DJ, Ntainjua EN, Edwards JK, Carley AF, Borisevich AY, Kiely CJ, Hutchings GJ, Science, 351(6276), 965 (2016)
Seo M, Lee DW, Han SS, Lee KY, ACS Catal., 7, 3039 (2017)
Seo M, Kim HJ, Han SS, Lee KY, Catal. Surv. from Asia, 21, 1 (2017)
Lee JW, Kim JK, Kang TH, Lee EJ, Song IK, Catal. Today, 293-294, 49 (2017)
Ye Y, Chun J, Park S, Kim TJ, Chung YM, Oh SH, Song IK, Lee J, Korean J. Chem. Eng., 29(9), 1115 (2012)
Kim JS, Kim HK, Kim SH, Kim I, Yu T, Han GH, Lee KY, Lee KY, Ahn JP, ACS Nano, 13, 4761 (2019)
Edwards JK, Edwin NN, Carley AF, Herzing AA, Kiely CJ, Hutchings GJ, Angew. Chem.-Int. Edit., 48, 8512 (2009)
Xiao X, Kang TU, Nam HB, Bhang SH, Lee SY, Ahn JP, Yu TY, Korean J. Chem. Eng., 35(12), 2379 (2018)
Jang YP, Nam HB, Song J, Lee SY, Ahn JP, Yu TK, Korean J. Chem. Eng., 36(9), 1417 (2019)
Edwards JK, Solsona B, Ntainjua EN, Carley AF, Herzing AA, Kiely CJ, Hutchings GJ, Science, 323, 1037 (2009)
Hu BZ, Deng WP, Li RS, Zhang QH, Wang Y, Delplanque-Janssens F, Paul D, Desmedt F, Miquel P, J. Catal., 319, 15 (2014)
Garcia T, Agouram S, Dejoz A, Sanchez-Royo JF, Torrente-Murciano L, Solsona B, Catal. Today, 248, 48 (2015)
Arrigo R, Schuster ME, Abate S, Giorgianni G, Centi G, Perathoner S, Wrabetz S, Pfeifer V, Antonietti M, Schlogl R, ACS Catal., 6, 6959 (2016)
Yook S, Kwon HC, Kim YG, Choi W, Choi M, ACS Sustain. Chem. Eng., 5, 1208 (2017)
Lee S, Jeong H, Chung YM, J. Catal., 365, 125 (2018)
Lee S, Chung YM, Mater. Lett., 234, 58 (2019)
Chung YM, Kwon YT, Kim TJ, Oh SH, Lee CS, Chem. Commun., 47, 5705 (2011)
Kim J, Chung YM, Kang SM, Choi CH, Kim BY, Kwon YT, Kim TJ, Oh SH, Lee CS, ACS Catal., 2, 1042 (2012)
Tian PF, Ouyang L, Xu XY, Ao C, Xu XC, Si R, Shen XJ, Lin M, Xu J, Han YF, J. Catal., 349, 30 (2017)
Tian PF, Ding DD, Sun Y, Xuan FZ, Xu XY, Xu J, Han YF, J. Catal., 369, 95 (2019)
Villa A, Freakley SJ, Schiavoni M, Edwards JK, Hammond C, Veith GM, Wang W, Wang D, Prati L, Dimitratos N, Hutchings GJ, Catal. Sci. Technol., 6, 694 (2016)
Menegazzo F, Signoretto M, Manzoli M, Boccuzzi F, Cruciani G, Pinna F, Strukul G, J. Catal., 268(1), 122 (2009)
Bernardotto G, Menegazzo F, Pinna F, Signoretto M, Cruciani G, Strukul G, Appl. Catal. A: Gen., 358(2), 129 (2009)