How Reproducible Are Surface Areas Calculated from the BET Equation?
Authors: Osterrieth Johannes , Rampersad James , Madden David G. , Rampal Nakul , Skoric Luka , Connolly Bethany , Allendorf Mark , Stavila Vitalie , SNIDER JONATHAN , Ameloot Rob , Marreiros Joao , Ania Conchi O. , Azevedo Diana C. S. , Vilarrasa-García Enrique , Santos Bianca F , Bu Xian-He , Zang Xe , Bunzen Hana , Champness Neil , Griffin Sarah L. , Chen Banglin , Lin Rui-Biao , Coasne Benoit , Cohen Seth M. , Moreton Jessica C. , Colon Yamil J. , Chen Linjiang , Clowes Rob , Coudert François-Xavier , Cui Yong , Hou Bang , D’Alessandro Deanna , Doheny Patrick W. , Dinca Mircea , Sun Chenyue , Doonan Christian , Huxley Michael , Evans Jack D. , falcaro paolo , Ricco Raffaele , Farha Omar K. , Idrees Karam B. , Islamoglu Timur , Feng Pingyun , Yang Huajun , Forgan Ross , Bara Dominic , Furukawa Shuhei , Sanchez Elisabeth , Gascon Jorge , Telalovic Selvedin , Ghosha Sujit K. , MUKHERJEE SOUMYA , Hill Matthew R. , Sadiq Muhammad Munir , Horcajada Patricia , Salcedo-Abraira Pablo , Kaneko Katsumi , Kukobat Radovan , Kenvin Jeffrey , Keskin Seda , Kitagawa Susumu , Otake Kenichi , Lively Ryan P. , DeWitt Stephen J. A. , Llewellyn Philip L. , Lotsch Bettina , Emmerling Sebastian T. , Pütz Alexander , Martí-Gastaldo Carlos , Muñoz Natalia , Garcia-Martinez Javier , Linares Noemi , Maspoch Daniel , Suarez Jose Antonio , Moghadam Peyman , Oktavian Rama , Morris Russell , Wheatley Paul , Navarro Jorge , Petit Camille , Danaci David , Rosseinsky Matthew , Katsoulidis Alexandros , Schroder Martin , Han Xue , Yang Sihai , Serre Christian , Mouchaham Georges , Sholl David , Thyagarajan Raghuram , Siderius Daniel , Snurr Randall Q. , Goncalves Rebecca B. , Ting Valeska , Rowlandson Jemma , Uemura Takeshi , Iiyuka Tomoya , van der Veen Monique , Rega Davide , Vanspeybroeck Veronique , Lamaire Aran , Rogge Sven , Walton Krista , Bingel Lukas W. , Wuttke Stefan , Andreo Jacopo , Yaghi Omar , Zhang Bing , Yavuz Cafer , Nguyen Thien , Zamora Felix , Montoro Carmen , Zhou Hong-Cai , Angelo Kirchon , Fairen-Jimenez David 
Published: March 2021

Porosity and surface area analysis play a prominent role in modern materials science, where 123 their determination spans the fields of natural sciences, engineering, geology and medical 124 research. At the heart of this sits the Brunauer-Emmett-Teller (BET) theory,[1] which has been 125 a remarkably successful contribution to the field of materials science. The BET method was 126 developed in the 1930s and is now the most widely used metric for the estimation of surface 127 areas of porous materials.[2] Since the BET method was first developed, there has been an 128 explosion in the field of nanoporous materials with the discovery of synthetic zeolites,[3] 129 nanostructured silicas,[4–6] metal-organic frameworks (MOFs),[7] and others. Despite its 130 widespread use, the manual calculation of BET surface areas causes a significant spread in 131 reported areas, resulting in reproducibility problems in both academia and industry. To probe 132 this, we have brought together 60 labs with strong track records in the study of nanoporous 133 materials. We provided eighteen adsorption isotherms and asked these researchers to 134 calculate the corresponding BET areas, resulting in a wide range of values for each one. We 135 show here that the reproducibility of BET area determination from identical isotherms is a 136 largely ignored issue, raising critical concerns over the reliability of reported BET areas in 137 the literature. To solve this major issue, we have developed a new computational approach 138 to accurately and systematically determine the BET area of nanoporous materials. Our 139 software, called BET Surface Identification (BETSI), expands on the well-known Rouquerol 140 criteria and makes, for the first time, an unambiguous BET area assignment possible.