A Scientometric Analysis of Catalysis Research

The outcomes of the present scientometric analysis of research in catalysis provide chemistry and catalysis scholars with a closer bibliometric knowledge of an old and central field of chemical research. The field nowadays is being reshaped by fundamental and technological advances spanning from single-atom heterogeneous catalysis to flow chemistry. Improving and widening research and education in catalysis is a strategic need for national economies. Four research policy guidelines aimed at fostering progress in catalysis research and education conclude the study.


INTRODUCTION
Almost as old as chemistry as a modern science based on the principles formulated by Lavoisier in the late 1700s, catalysis entered chemistry research in 1835. At that time Berzelius introduced the term "catalysis" to indicate "the decomposition of bodies by this force in the same way that one calls by the name analysis the decomposition of bodies by chemical affinity". [1] According to Berzelius the catalytic force in question, "very different from chemical affinity", was exerted by "simple and compound bodies" on other bodies. [1] In simple terms, catalysis is a phenomenon related to acceleration of the rates of chemical reactions in the presence of substances (catalysts), which remain formally unchanged during the reaction. In reality, the catalysts are involved in forming chemical bonds with the reactants during so-called catalytic cycles.
An instructive account on the historic development of the catalysis concept and its explanation was published by Wisniak in 2009. [2] The study goes from Berzelius until the first two Nobel prizes awarded in 1909 to Oswald and in 1912 to Sabatier. The latter was awarded for his work on hydrogenation of organic compounds in the presence of metals, namely the catalytic hydrogenation of unsaturated organic molecules using "finely divided" Ni obtained by reducing nickel hydroxide with H 2 at 250°C.
A brief, but still very interesting history of catalysis dividing its historical development into five distinct periods was published by scholars in Sweden in 2013. [3] Only a few scientometric study on catalysis have been published so far. In 2014, Zibareva and co-workers published two bibliometric analyses. The first was aimed to identify "hot topics" in catalysis research, namely photocatalysis, electrocatalysis, stereoselective catalysis, biocatalysis, catalytic functionalization of organic compounds, nanocatalysis via graphene-based materials, biofuel catalytic production and catalysis in new energy technology. [4] The second one was aimed specifically at a bibliometric analysis of publications including the term "nanocatalysis". It was concluded that "nanocatalysis" was a new research subject pertaining both to nanotechnology and to catalysis science. [5] Though focused on a scientometric assessment of Indian publications in catalysis between 2006 and 2015, the first comprehensive study on catalysis was reported by Siddaiah and co-workers in 2016 in an open access journal aimed primarily at librarians. [6] According to Dhawan et al. the overall number of research articles in catalysis was found to have grown at 5.78% annual growth rate, going from 6,907 publications in 2006 to 11,303 in 2015. [6] These findings are consistent with the rapid growth in knowledge production in chemistry between 1990 and 2009. Moreover, during this period because of profound changes in the chemical research process there was a clear shift towards multidisciplinary and collaborative research carried out by scholars from other disciplines and from different countries. [7] Journal of Scientometric Research, Vol 9, Issue 3, Sep-Dec 2020 Catalysis is at the core of chemical manufacturing, incorporating not only production of hydrocarbon fuels in various oil refineries around the globe but also of virtually all chemicals, including both bulk and fine chemicals. Apart from few exceptions catalytic technologies employed in industry comprising both catalyst manufacture and application in chemical reactors are proprietary.
Once the patents have been filed, similar to scientists from academia, industrial researchers also publish in chemistry and catalysis journals. The justification for such policy was recently formulated in the following way: "publication becomes… a valuable tool to profile the expertise of a company to the scientific community and find partners, in order to initiate bilateral collaborations or other publicly funded projects with university. In a similar way, the innovation potential of a company becomes visible via publications, increasing its prestige". [8] The paucity of scientometric studies in catalysis science and technology is accompanied by a similar low number of studies devoted to contemporary catalysis education. This is somewhat surprising considering a widespread need perceived in many countries for better education in catalysis. [9,10] This study critically presents the outcomes of a scientometric analysis of research in catalysis. Discussion is put in context of scientific publishing in the modern digital era. A particular feature of contemporary research is an increase in the number of preprints, which became rather popular in the fields adjacent to chemistry. This slowly but inexorably impacts the dissemination of chemical knowledge. [11] Moreover, chemical manufacturing is experiencing some sort of renaissance related to emerging fields of green and sustainable process chemistry technology, compliant with circular economy.
Researchers in chemistry, including those involved in catalysis, need knowledge of scientometric tools like the h-index [12] and scientometry in general. Indeed, regardless of thoughtful pleas for quality and scientific impact, often researchers are evaluated based on examining the journal impact factor of the published papers only. [13] Subsequently different metrics (e.g. h-index) are regularly used by universities and research agencies as a "decision-making tool" to evaluate both single researchers and entire university departments. In the latter case it can be done via the mean h-index of the researchers working there. [14] We agree with Barnes: the scholarly debate on science metrics currently confined to highly technical discussions in specialized journals [13] needs to shift from the latter journals to the main scientific journals and preprint servers regularly used by researchers active in that field. This study serves to this scope in the important chemistry research field of catalysis.
The research policy guidelines concluding the study are aimed at fostering progress in catalysis research, education and industrial uptake in economically developed and developing countries.

RESEARCH AND PUBLISHING IN CATALYSIS
Ending his "On Catalysis" Nobel lecture given on December 12, 1909, Ostwald noted how the scientific field of catalysis was "in the first stages of its development. At present the main task is still essentially to discover and scientifically to establish the various cases of catalysis". [15] Sabatier followed suit publishing in 1913 La Catalyse en Chimie Organique, [16] a book so rich of valuable information about the fundamentals of catalysis that the English. The English translation of that book published in 1922 is still read and commented at advanced catalysis courses more than a century later. [17] The first catalytic use of gold, up to that time and many decades after considered chemically unreactive, was reported in 1913 by Fokin. He used asbestos as a support of the finely divided gold nanoparticles in a industrially important reaction of methanol oxidative dehydrogenation to formaldehyde [18] (today carried out in industry using either silver or iron catalysts).
Fokin also discovered that Au and Ag powders were more active than supported Pt. Sabatier referred to Fokin's work in La Catalyse en Chimie Organique. Eventually, the latter book in 1922 was translated into English, [19] but these published findings were forgotten until Haruta and co-workers in 1987 reported the high catalytic activity of gold nanoparticles in low-temperature CO oxidation. [20] In the times of Sabatier and many decades thereafter the most important achievements in catalysis were published in general chemistry journals.
The first international catalysis journal specifically devoted to catalysis was Kinetics and Catalysis, namely the English translation of the Russian journal Kinetika i Kataliz founded in 1960 by Boreskov, Balandin and other prominent scientists at the Academy of Sciences of the USSR. Two years later the Journal of Catalysis was established by the Academic Press.
In the preface to the first issue of Catalysis Reviews launched in 1968 Heinemann wrote "catalysis is involved in one or the other step of manufacture of almost one-half of our industrial and agricultural product, yet it is less structured, less understood, still less of a science and more of an art than many other fields of smaller importance to our daily lives". Reflecting the rapid rise of publications in the field which occurred since the early 2000s, [6] several scientific publishers established new catalysis journals (Table 1).
Similarly to chiral ferrocenylphosphine ligands for asymmetric catalytic hydrosilylation of ketones introduced in 1974, [23] the catalysts developed by the Nobel laureates mentioned above and by several other chemists are widely used nowadays in manufacturing of fine and specialty chemicals, vitamins and other active pharmaceutical ingredients.
The almost contemporary emergence, in the early 1990s, of nanochemistry and green chemistry oriented to wasteprevention rather than waste control, drove a second wave of progress in catalysis science and technology.
A number of developed bottom-up material synthetic routes appeared such as the sol-gel and hydrothermal ones often "assisted" by microemulsion templates. These routes along with new surface chemical functionalization strategies enabled reproducible and robust preparation of nanostructured catalytic materials of high activity, selectivity and stability. [24] These materials are suitable for use in various application areas of catalysis, including less conventional ones, such as producing pharmaceutical "generics" with dramatically reduced reaction times, solvent utilization and waste production. [25] Note that conventional, so-called stoichiometric production routes, used in manufacturing fine chemicals (10,000 t/a demand) and pharmaceuticals (1,000 t/a demand) generate substantial amounts of waste in general, reaching in the worst cases 100 kg of waste per kg of the manufactured product. [26]

SCIENTOMETRIC ANALYSIS
The scientometric assessment of research in catalysis referring to the 2006-2015 period shows that China led the ranking with 28.1% of the global share of research articles in the field, followed by the USA with 14.9% of the share. [5] The other countries in the ranking were Japan, India, Germany, France, South Korea, Iran, Spain and Great Britain. Together these first 10 countries accounted for 82.5% of the global publication share in the catalysis research output.
Following the same approach a scientometric assessment of research articles in catalysis published in indexed scientific journals between 2015 and November 13, 2020 (Table 2) was obtained in this work by carrying out a search in Scopus using the words "catalysis" or "catalyst" present in the title, abstract or keywords.
Limited to documents published in English in the form of research articles or reviews (excluding book chapters, conference papers and erratum communications), the search returned 279,829 documents. Of these, 279,042 were published in scientific journals, 623 in book series, 149 in trade journals, 12 in books and 3 in conference proceedings. All these and related catalysis journals today publish research articles and reviews from all types of catalysis including heterogeneous catalysis, homogeneous catalysis, biocatalysis, electrocatalysis, photocatalysis, nanocatalysis and organocatalysis.
Following the 1950-1977 development of organometallic catalysis, [22] for which in 1963 the Nobel prize in chemistry was awarded to Natta and Ziegler for olefin polymerization and in 1973 to Fisher and Wilkinson for new olefin hydroformylation catalysts, the prestige of catalysis as an academic discipline increased again since the early 2000s. Interestingly the share of the leading countries (top 20 in Table 2) even increased in the last five years amounting to 83.9% of all papers in English published in journals indexed by Scopus, with China (28.8%) dominating even further. Germany surpassed Japan and Iran managed to remain amid the world's top 10 countries for research in catalysis regardless economic sanctions that, for example, slow down or even impede purchase of chemical reactants from academic laboratories in that country.
Other countries worth mentioning are Italy (12 th in the global ranking) and Russia (11 th in the ranking list). Russia, for example, hosts since 1958 the world's largest academic centre in the field of catalysis, the renowned Boreskov Institute of Catalysis, which is nowadays incorporated in the Russian Academy of Sciences. [27] In Russia, since the 2006 new science policy allocates funds and grants depending on the research assessment based on publications in the international literature. Since then, the number of research papers published in English in all scientific fields including chemistry dramatically increased. The current policy in Russia also drives institutions outside of three main scientific cities (Moscow, St. Petersburg and Novosibirsk) to enter the international arena in a way similar to that followed by China in the last three decades with several leading universities and research centres today located well beyond China's two main cities (Beijing and Shanghai).
Indeed, amid the first twenty institutions including umbrella organizations (e.g. academies of sciences and national research councils) only few are not Chinese (Table 3), representing France, Russia and Spain.
As can be seen from Table 4 globally not chemical companies, but rather public funding organizations are responsible for financial support of scholars working in the field of catalysis. Contrary to Table 3 there is more diversity in top funding organizations representing not only China, but other Asian countries, Europe, including European Research Council and both North and South America.
It is instructive to analyze the top chemical journals which publish papers in the field of catalysis (Table 5). Among the top 10 two journals specialize only in catalysis (ACS Catalysis and Applied Catalysis B: Environmental), two specialize in materials and organic chemistry while the remaining ones are     The graph in Figure 1 shows that the yearly number of studies is constantly increasing reflecting the steady attention to the field of catalysis in industry and academia.
To understand the scope of the growth of research in catalysis science and technology it is enough to learn that a similar search for original research and review articles published in English limited to year 2000 returned 16,339 documents. In plant resembles the same lean production mode used by the most advanced manufacturing industries. [30] This shift in the paradigm requires new skills and much broader utilization of chemical engineering practices, which were often in the periphery of process development focusing otherwise on chemistry.
The increasing shortage of APIs, especially of generics, in many developed and developing countries culminated with shortage of hydroxychloroquine (HCQ) used to treat COVID-19 patients. Such situation, which in early 2020 led India to dramatically scale up production for donating the drug to more than 50 countries, [31] has made it clear that countries cannot rely any longer on API and fine chemical imports.
The creation from scratch of a national fine chemical and pharmaceutical industry in African, Asian, Latin American and European countries is now possible. Followed by South Africa with 1,859 publications in the field of catalysis in 2015-2020 (November 13, 2020) period, with 2,258 publications Egypt leads the rank of African countries. Algeria (788), Tunisia (581) and Morocco (429) rank third, fourth and fifth. The impact of COVID-19 epidemics in North African countries was very limited. In Morocco the government acquired all HCQcontaining drugs locally manufactured by a foreign company on March 2020. [32] Algeria took similar initiative at the same time negotiating with two pharmaceutical groups the purchase of large quantities of drugs using hydroxychloroquine as API both produced in Algeria and imported. [33] Tunisia begun manufacturing hydroxychloroquine locally. [34] The latter non-steroidal drug with anti-inflammatory activity, a generic widely used also for the treatment of rheumatoid arthritis, can be manufactured under flow conditions with an yield improvement of 52% compared to the commercial process. The technology combines two packed bed reactors with one batch reactor used for heterogeneously catalyzed reductive amination and hydrogenation steps, affording direct conversion of the starting materials to HCQ. [35] The example can be generalized. Most synthetic routes for the production of fine chemicals and APIs can now be carried out under flow using heterogeneous catalysts. These routes utilizing also single-atom catalysts, [36] are approaching commercialization at a fraction of the cost of conventional routes in much smaller chemical factories scattered across countries. Under these conditions, chemistry professionals specializing in catalysis and contemporary process chemistry should be in strong demand for all countries willing to become at least partly self-sufficient in the production of life-saving drugs.
other words, the scientific output in catalysis has more than tripled, largely due to contributions of scholars based in Asia, predominantly in China and India, but also in South Korea and in Iran. An old research field historically dominated by researchers based in USA, Europe and Japan is now largely dominated by China. With over 1.35 billion inhabitants growing at a fast pace and a vibrant chemistry and chemical engineering school growing rapidly in terms of quality, quantity, funding and international collaborations, [28] India is likely to surpass contributions from the USA within the next decade.

EXPANDED SCOPE OF CATALYSIS RESEARCH
From the economic viewpoint research in catalysis is particularly important because, through further organic process development, it enables the production of virtually all chemical substances, including value-added fine and specialty chemicals and active pharmaceutical ingredients (APIs).
Certainly, utilization of continuous production technologies is a common place in production of fuels and bulk chemicals, However, utilization of the same practices in manufacturing of fine chemicals is reshaping the industry at the global level. Until the advent of flow chemistry production processes, manufacturing fine chemicals and APIs, requiring significant capital and operational expenses (CAPEX and OPEX, respectively), was limited to developed countries with long chemical traditions. Different European countries including those formerly belonging to the Soviet block, as well as countries in North America can be mentioned in this context. In other places (e.g. China and India) production was outsourced to companies identified in the chemical business jargon as "custom manufacturing organizations" (CMOs). [29] Coupled to the new generation heterogeneous catalysts, flow chemistry dramatically lowers both CAPEX and OPEX costs. The former costs are dramatically reduced because large batch reactors equipped with complex temperature, mixing and pressure control tools are replaced by one or more small flow reactors. This enables far better controlled, safer and milder reaction conditions.
The latter costs fall because as already noted by Pollak in 2011 in the preface to his reference book devoted to the fine chemical industry the "most progressive companies adopt lean production principles originally developed for the automotive industry". [29] Continuous production in small and modular flow reactors with new generation solid catalysts prevents the formation of unwanted by-products, eliminates the need for separation of catalysts and products and shortens time to market. Production becomes truly driven by customer demand preventing overproduction. In this way operating a fine chemicals Journal of Scientometric Research, Vol 9, Issue 3, Sep-Dec 2020

OUTLOOK AND CONCLUSION
The field of catalysis is growing and changing its geography. This becomes apparently evident from the analysis of the top organizations, funding agencies and number of papers published by scholars representing different countries. The field is also expanding beyond its conventional borders comprising classical areas of oil refining, chemicals manufacturing and pollution control, to include also production of pharmaceuticals.
In this context, improving and broadening research and education in catalysis becomes a strategic need for governments and national economies. Four main guidelines, two for governments and two aimed at chemical companies, emerge from the present scientometric analysis and related studies on the global reshaping of the chemical industry. [37] First, aware that catalysis and process chemistry are the key enabling technologies of the chemical industry, governments should support the creation of dedicated research centres as done for example in Russia with the Boreskov Institute of catalysis. [27] We are already witnessing such initiatives across the globe which in fact allow different research and educational institutions achieve the required critical mass to act as purposeful partners of the chemical industry.
Second, in most countries education in catalysis at the undergraduate level is generally not adequate, lacking uniformity [9] and suffering from a still fragmented approach to its sub-disciplines. [10] To overcome such situation, the example of Germany should be followed, where a national curriculum (Lehrprofil Katalyse) was created in 1993 being since then constantly updated.
Third, aware of the unique economic relevance of catalysis, chemical companies should start effective collaboration with public research centres thereby increasing the research and development (R&D) capacity of local firms and entrepreneurs and innovation capacity of young researchers. There are many ways to do that. Among examples known to the authors Germany, France, Finland and Switzerland should be mentioned. Worth emulating is, for instance, Switzerland where regular professional workshops between industry's and academic researchers are organized. [38] Fourth, chemical companies should learn from what happened to manufacturers of gas-powered turbines whose market shrank from 60 GW in 2014 to 31 GW in 2018, [39] due to completely unforeseen and rapid global uptake of wind and photovoltaic power generation across the world. [40] Considering that renewable power coupled with the demand and development of Li-ion batteries is cheaper than the gas generation even without subsidies, [41] it is highly unlikely that the market for gas-powered turbines will ever recover.
The same will shortly happen with flow chemistry and new catalytic technology in chemical manufacturing. After more than two decades in which green chemistry remained mostly confined to academic research papers and conferences, [42] the falling costs of flow chemistry reactors coupled to the increasing availability of completely new heterogeneous catalysts provides a highly profitable business opportunity for all new fine chemical manufacturers. For example, using novel green technologies new or existing companies might start producing the APIs of generic medicines in increasing shortage [43] at a fraction of the cost of competitors utilizing old production technology in batch reactors.
Now that regulatory agencies in most countries allow the use of flow chemistry for manufacturing APIs and fine chemicals, it is enough to analyze the sales of industrial flow reactors to learn that the process has already started. [44] ACKNOWLEDGEMENT I.L. Simakova acknowledges Ministry of Science and Higher Education of the Russian Federation for the financial support.