[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-45372-en":3,"doc-seo-45372-105":30,"detail-sidebar-cat-0-en-105":95},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":20,"is_deleted":4,"is_public":21,"is_downloadable":21,"audit_status":21,"page_count":22,"language":23,"language_code":24,"site_id":25,"html_lang":24,"table_of_contents":26,"faqs":27,"seo_title":13,"seo_description":14,"update_tm":28,"read_time":29},45372,1099513958762,"Logic","https://ap-avatar.wpscdn.com/avatar/1000023916a998db790?x-image-process=image/resize,m_fixed,w_180,h_180&k=1782109480056885918",8,"Research & Report","The Concept of Active Site in Heterogeneous Catalysis","Catalysis is central to chemistry and is expected to support the transition toward a more renewable and circular society. The review explains the physical meaning of the active site in heterogeneous catalysis and evaluates common approaches for linking catalyst performance to turnover frequency and for interpreting structure sensitivity or insensitivity. Concepts from enzymatic and homogeneous catalysis are compared to clarify how solid catalysts challenge active-site definition, enabling future tailoring of active-site function using modern experimental and theoretical tools.","Turnover frequency  \nThe turnover frequency is defined as the turnover unit per time. For most industrial applications, the turnover frequency is 10−3–102.  \nStructure sensitivity A reaction in which not all surface sites have the same activity. The surfacenormalized activity changes with nanoparticle size for structure-sensitive reactions.  \n1Inorganic Chemistry and Catalysis, Debye institute for Nanomaterials, Utrecht University, Utrecht, Netherlands.  \n2Schulich Faculty of Chemistry, Technion – Israel Institute of Technology, Haifa, Israel.  \n✉e-mail:  \n[C.Vogt@technion.ac.il](C.Vogt@technion.ac.il);  \n[B.M.Weckhuysen@uu.nl](B.M.Weckhuysen@uu.nl)  \n[https://doi.org/10.1038/](https://doi.org/10.1038/)[ ](https://doi.org/10.1038/)[s41570-021-00340-y](s41570-021-00340-y)  \nREvIEWS  \nThe concept of active site in heterogeneous catalysis  \nCharlotte Vogt1,2 ✉ and Bert M. Weckhuysen1 ✉  \nAbstract | Catalysis is atthe core of chemistry and has been essential to make all the goods surrounding us, including fuels, coatings, plastics and other functional materials. In the near future, catalysis will also be an essential tool in making the shift from a fossil-fuel-based to amore renewable and circular society. To make this reality, we have to better understand the fundamental concept of the active site in catalysis. Here, we discuss the physical meaning—and deduce the validity and, therefore, usefulness—of some common approaches in heterogeneous catalysis, such as linking catalyst activity to a ‘turnover frequency’ and explaining catalytic performance in terms of ‘structure sensitivity’ or ‘structure insensitivity’. Catalytic concepts from the fields of enzymatic and homogeneous catalysis are compared, ultimately realizing that the struggle that one encounters in defining the active site in most solid catalysts is likely the one we must overcome to reach our end goal: tailoring the precise functioning of the active sites with respect to many different parameters to satisfy our ever-growing needs. This article ends with an outlook of what may become feasible within the not-too-distant future with modern experimental and theoretical tools at hand.  \nThe global revenue of the chemical industry in 2019 amounted to an approximate US$4 trillion1, of which an estimated 85% involved catalytic processes2. Few things in catalysis are as important—yet, as elusive—as the concept of the active site. The active site is what makes a catalyst work. It brings, as we know from the landmark studies of Wilhelm Ostwald (1853–1932), Svante Arrhenius (1859–1927) and Jacobus van ‘t Hoff (1852–1911), the kinetics of a chemical reaction in disbalance. This generally lowers the activation energy and, thus, increases the speed of a desired chemical reaction, leaving the reaction’s thermodynamics unaffected (Fig. 1a). Heterogeneous catalysis is a diverse and highly interdisciplinary field, which combines knowledge from materials and surface science, physical, analytical and theoretical chemistry, chemical engineering and, not least, organic and inorganic chemistry. By combining advanced knowledge in synthesis techniques3–7, with strides in space-resolved and time-resolved analytical methods8–12, as well as advanced theoretical knowledge for computational modelling13–16, one can argue that we are at the doorstep to the era of rational catalyst and process design. Defining the ‘active site’ along with the various actors that determine its activity are the ingress to conceptualizing the necessary novel catalysts, concepts and processes to tackle some of the immense challenges modern society faces, such as the quest for an energy transition or a circular society aiding to abate climate change.  \nAs such, in this Review, we discuss the physical meaning — and deduce the validity and, therefore, usefulness—of some common approaches in heterogeneous catalysis, such as linking catalyst activity to a‘turnover frequency’ and explaining catalytic performance in terms of ‘str","cbCaipT3TSzCqjNA","https://ap.wps.com/l/cbCaipT3TSzCqjNA","pdf",5511469,2,1,23,"English","en",105,"# The concept of active site in heterogeneous catalysis\n## The active site in a solid catalyst","[{\"question\":\"What is the active site and why is it important in heterogeneous catalysis?\",\"answer\":\"The active site is the location that makes a catalyst work by bringing the reaction kinetics into balance, typically lowering activation energy and increasing reaction speed while leaving thermodynamics largely unaffected.\"},{\"question\":\"How does turnover frequency relate to catalyst activity?\",\"answer\":\"Turnover frequency is defined as the turnover unit per time, and it is used to link observed catalyst activity to a measurable kinetic concept across applications.\"},{\"question\":\"What does structure sensitivity mean in this context?\",\"answer\":\"Structure sensitivity describes reactions where surface sites differ in activity, causing surfacenormalized activity to change with nanoparticle size; structure insensitivity is treated as the contrasting interpretation.\"},{\"question\":\"How do heterogeneous catalysts complicate defining the active site?\",\"answer\":\"Solid catalysts are affected by multidimensional factors across multiple scales, including porosity, phase and morphological transformations over time, which can shift observed activity away from a single static site definition.\"}]",1783458721,58,{"code":4,"msg":31,"data":32},"ok",{"site_id":25,"language":24,"slug":33,"title":13,"keywords":34,"description":14,"schema_data":35,"social_meta":90,"head_meta":92,"extra_data":94,"updated_unix":28},"the-concept-of-active-site-in-heterogeneous-catalysis","",{"@graph":36,"@context":89},[37,53,68],{"@type":38,"itemListElement":39},"BreadcrumbList",[40,44,47,50],{"item":41,"name":42,"@type":43,"position":21},"https://docshare.wps.com","Home","ListItem",{"item":45,"name":46,"@type":43,"position":20},"https://docshare.wps.com/document/","Document",{"item":48,"name":12,"@type":43,"position":49},"https://docshare.wps.com/document/research-report/",3,{"item":51,"name":13,"@type":43,"position":52},"https://docshare.wps.com/document/the-concept-of-active-site-in-heterogeneous-catalysis/45372/",4,{"url":51,"name":13,"@type":54,"author":55,"headline":13,"publisher":57,"fileFormat":60,"inLanguage":24,"description":14,"dateModified":61,"datePublished":62,"encodingFormat":60,"isAccessibleForFree":63,"interactionStatistic":64},"DigitalDocument",{"name":9,"@type":56},"Person",{"url":41,"name":58,"@type":59},"DocShare","Organization","application/pdf","2026-07-18","2026-07-07",true,{"@type":65,"interactionType":66,"userInteractionCount":20},"InteractionCounter",{"@type":67},"ViewAction",{"@type":69,"mainEntity":70},"FAQPage",[71,77,81,85],{"name":72,"@type":73,"acceptedAnswer":74},"What is the active site and why is it important in heterogeneous catalysis?","Question",{"text":75,"@type":76},"The active site is the location that makes a catalyst work by bringing the reaction kinetics into balance, typically lowering activation energy and increasing reaction speed while leaving thermodynamics largely unaffected.","Answer",{"name":78,"@type":73,"acceptedAnswer":79},"How does turnover frequency relate to catalyst activity?",{"text":80,"@type":76},"Turnover frequency is defined as the turnover unit per time, and it is used to link observed catalyst activity to a measurable kinetic concept across applications.",{"name":82,"@type":73,"acceptedAnswer":83},"What does structure sensitivity mean in this context?",{"text":84,"@type":76},"Structure sensitivity describes reactions where surface sites differ in activity, causing surfacenormalized activity to change with nanoparticle size; structure insensitivity is treated as the contrasting interpretation.",{"name":86,"@type":73,"acceptedAnswer":87},"How do heterogeneous catalysts complicate defining the active site?",{"text":88,"@type":76},"Solid catalysts are affected by multidimensional factors across multiple scales, including porosity, phase and morphological transformations over time, which can shift observed activity away from a single static site definition.","https://schema.org",{"og:url":51,"og:type":91,"og:title":13,"og:site_name":58,"og:description":14},"article",{"robots":93,"canonical":51},"index,follow",{"doc_id":7,"site_id":25},{"code":4,"msg":5,"data":96},[97,101,105,109,114,119,124,127,132,135,139],{"id":21,"doc_module":4,"doc_module_name":46,"category_name":98,"show_sort_weight":99,"slug":100},"Story & Novel",90,"story-novel",{"id":20,"doc_module":4,"doc_module_name":46,"category_name":102,"show_sort_weight":103,"slug":104},"Literature",80,"literature",{"id":52,"doc_module":4,"doc_module_name":46,"category_name":106,"show_sort_weight":107,"slug":108},"Exam",70,"exam",{"id":110,"doc_module":4,"doc_module_name":46,"category_name":111,"show_sort_weight":112,"slug":113},5,"Comic",60,"comic",{"id":115,"doc_module":4,"doc_module_name":46,"category_name":116,"show_sort_weight":117,"slug":118},6,"Technology",50,"technology",{"id":120,"doc_module":4,"doc_module_name":46,"category_name":121,"show_sort_weight":122,"slug":123},7,"Healthcare",40,"healthcare",{"id":11,"doc_module":4,"doc_module_name":46,"category_name":12,"show_sort_weight":125,"slug":126},30,"research-report",{"id":128,"doc_module":4,"doc_module_name":46,"category_name":129,"show_sort_weight":130,"slug":131},9,"Religion & Spirituality",20,"religion-spirituality",{"id":130,"doc_module":4,"doc_module_name":46,"category_name":133,"show_sort_weight":130,"slug":134},"World Cup","world-cup",{"id":136,"doc_module":4,"doc_module_name":46,"category_name":137,"show_sort_weight":136,"slug":138},10,"Lifestyle","lifestyle",{"id":140,"doc_module":4,"doc_module_name":46,"category_name":141,"show_sort_weight":110,"slug":142},19,"General","general"]